Various cmake changes

Mostly from suggestions, but there's a couple of other minor
fixes and additions:

   Cmake not decides with SDK to use on Windows

   All Audacity cmake options are not prefixed with "audacity_", but this
   is configurable in audacity/CMakeLists.txt

   Several other options have been marked advanced so they don't clutter
   the CMake GUI

   On Windows, multiple processors will now be used reducing build time
   considerably

   Quieted a couple of package messages that the user doesn't need to see

   No longer tried to create aliases on Windows

   No longer used precompiled headers if ccache is available

   On Windows, only copies the needed wxWidgets and VC runtime libraries
   to the bin directory

CMakeLists.txt

@@ -29,28 +29,25 @@ cmake_policy( SET CMP0072 NEW )
 cmake_policy( SET CMP0075 NEW )
 
 if( WIN32 )
-
    # The NuGet packages that the Windows build requires
    # (Only here for visibility)
    set( GETTEXT_NAME "Gettext.Tools" )
    set( GETTEXT_VERSION "0.20.1.1" )
    set( PYTHON_NAME "python2" )
    set( PYTHON_VERSION "2.7.17" )
-
-   # Define the SDK version we require
-   set( CMAKE_SYSTEM_VERSION "10.0.17763.0" CACHE INTERNAL "" )
-
 elseif( APPLE )
-
    # Define the OSX compatibility parameters
    set( CMAKE_OSX_ARCHITECTURES x86_64 CACHE INTERNAL "" )
    set( CMAKE_OSX_DEPLOYMENT_TARGET 10.7 CACHE INTERNAL "" )
    set( CMAKE_OSX_SYSROOT macosx CACHE INTERNAL "" )
 
-   # A bit of a no-no, but couldn't figure out a better way to make it GLOBAL
-   set( CMAKE_CXX_FLAGS "-stdlib=libc++" )
+   # Shouldn't cmake do this???
+   string( APPEND CMAKE_CXX_FLAGS " -stdlib=libc++" )
 endif()
 
+# Define option() prefix
+set( _OPT "audacity_" )
+
 # Add our module path
 set( CMAKE_MODULE_PATH ${CMAKE_SOURCE_DIR}/cmake-proxies/cmake-modules)
 
@@ -59,14 +56,16 @@ set( CMAKE_MODULE_PATH ${CMAKE_SOURCE_DIR}/cmake-proxies/cmake-modules)
 #set( CMAKE_INTERPROCEDURAL_OPTIMIZATION_RELEASE ON )
 #set( CMAKE_INTERPROCEDURAL_OPTIMIZATION_DEBUG OFF )
 
-# Set the required C++ stardard
+# Set the required C++ standard
 set( CMAKE_CXX_STANDARD 14 )
 set( CMAKE_CXX_STANDARD_REQUIRED ON )
 
 # Use ccache if available
 find_program( CCACHE_PROGRAM ccache )
+mark_as_advanced( FORCE CCACHE_PROGRAM )
+
 if( CCACHE_PROGRAM )
-    set_property( GLOBAL PROPERTY RULE_LAUNCH_COMPILE "${CCACHE_PROGRAM}" )
+   set_property( GLOBAL PROPERTY RULE_LAUNCH_COMPILE "${CCACHE_PROGRAM}" )
 endif()
 
 # Our very own project
@@ -88,12 +87,26 @@ include( TestBigEndian )
 # Organize subdirectories/targets into folders for the IDEs
 set_property( GLOBAL PROPERTY USE_FOLDERS ON )
 
-# Make sure Audacity is the startup project on Windows
 if( CMAKE_GENERATOR MATCHES "Visual Studio" )
+   # Make sure Audacity is the startup project
    set_directory_properties(
       PROPERTIES
          VS_STARTUP_PROJECT "${CMAKE_PROJECT_NAME}"
    )
+
+   # Build using multiple processors
+   foreach( config ${CMAKE_CONFIGURATION_TYPES} )
+      string( TOUPPER "${config}" config )
+      string( APPEND CMAKE_C_FLAGS_${config} " /MP" )
+      string( APPEND CMAKE_CXX_FLAGS_${config} " /MP" )
+   endforeach()
+
+   # Define system library information, but we'll do the install
+   set( CMAKE_INSTALL_SYSTEM_RUNTIME_LIBS_SKIP YES )
+   set( CMAKE_INSTALL_UCRT_LIBRARIES NO )
+   set( CMAKE_INSTALL_MFC_LIBRARIES NO )
+   set( CMAKE_INSTALL_OPENMP_LIBRARIES NO )
+   include( InstallRequiredSystemLibraries )
 endif()
 
 # Where the final product is stored
@@ -127,6 +140,9 @@ endif()
 # Add the dynamic linker library (if needed) to the list of required libraries
 list( APPEND CMAKE_REQUIRED_LIBRARIES ${CMAKE_DL_LIBS} )
 
+# Make sure they're used during the link steps
+set( CMAKE_LINK_INTERFACE_LIBRARIES ${CMAKE_REQUIRED_LIBRARIES} )
+
 # May be a misconfiguration in my system, but CMake doesn't want to look
 # in /usr/local/lib by default...so force the issue
 if( CMAKE_SYSTEM_NAME MATCHES "FreeBSD" )
@@ -135,13 +151,10 @@ if( CMAKE_SYSTEM_NAME MATCHES "FreeBSD" )
    list( APPEND CMAKE_SHARED_LINKER_FLAGS -L/usr/local/lib )
 endif()
 
-# Make sure they're used during the link steps
-set( CMAKE_LINK_INTERFACE_LIBRARIES ${CMAKE_REQUIRED_LIBRARIES} )
-
-# Various common checks whose results are used by the various targets
+# Various common checks whose results are used by the different targets
 test_big_endian( WORDS_BIGENDIAN )
 
-# Check for various compiler flags
+# Check for compiler flags
 if( CMAKE_CXX_COMPILER_ID MATCHES "AppleClang|Clang|GNU" )
    check_cxx_compiler_flag( "-mmmx" HAVE_MMX )
    if( HAVE_MMX )
@@ -239,10 +252,10 @@ check_type_size( "wchar_t" SIZEOF_WCHAR LANGUAGE C )
 check_type_size( "void*" SIZEOF_POINTER LANGUAGE C )
 
 # We'll be using it if it's available
-find_package( PkgConfig )
+find_package( PkgConfig QUIET )
 
 # Mostly just to make the CMP0072 policy happy
-find_package( OpenGL )
+find_package( OpenGL QUIET )
 
 # When called will define several useful directory paths for the 
 # current context.
@@ -265,9 +278,10 @@ endmacro()
 # So, in either case we end up with what we want:
 #     .../bin/Debug//
 # or:
-#     .../bin/./Debug
+#     .../bin//Debug
 set( _DEST "${CMAKE_RUNTIME_OUTPUT_DIRECTORY}/${CMAKE_CFG_INTDIR}/${CMAKE_BUILD_TYPE}" )
 set( _EXEDIR "${_DEST}" )
+string( REGEX REPLACE "/+$" "" _EXEDIR "${_EXEDIR}" )
 
 # Adjust them for the Mac
 if( CMAKE_SYSTEM_NAME MATCHES "Darwin" )
@@ -286,7 +300,9 @@ if( NOT EXISTS "${CMAKE_BINARY_DIR}/lib" )
    file( MAKE_DIRECTORY "${CMAKE_BINARY_DIR}/lib" )
 endif()
 
-if( NOT EXISTS "${CMAKE_BINARY_DIR}/lib64" )
+# Only create on systems that need it, effectively excluding Windows where links
+# may not work due to insufficient privileges
+if( NOT CMAKE_INSTALL_LIBDIR STREQUAL "lib" AND NOT EXISTS "${CMAKE_BINARY_DIR}/lib64" )
    file( CREATE_LINK "${CMAKE_BINARY_DIR}/lib" "${CMAKE_BINARY_DIR}/lib64" SYMBOLIC )
 endif()
 
@@ -379,11 +395,11 @@ add_subdirectory( "cmake-proxies/mod-script-pipe" )
 #[[
    get_cmake_property(_variableNames VARIABLES)
    foreach (_variableName ${_variableNames})
-   message(STATUS "${_variableName}=${${_variableName}}")
+      message(STATUS "${_variableName}=${${_variableName}}")
    endforeach()
 #]]
 #[[
    include(PrintProperties)
-   print_properties(TARGET "Audacity")
+   print_properties(TARGET "wxWidgets")
 #]]