Updates the cmake build system

It's still has some work, but it successfully builds on
all 3 main platforms.  Some of the outstanding items
include:

   Install target testing (mostly important for Linux)
   CMakeList clean up and comments
   Debug and Release build verification
   Audit of compile/link options
   Need a Mac signed and notarized build
   (and probably more)

cmake-proxies/lib-widget-extra/CMakeLists.txt

@@ -0,0 +1,26 @@
+
+add_library( ${TARGET} STATIC )
+
+list( APPEND SOURCES
+   PRIVATE
+      ${TARGET_ROOT}/NonGuiThread.cpp
+)
+
+list( APPEND INCLUDES
+   PUBLIC
+      ${TARGET_ROOT}
+)
+
+list( APPEND LIBRARIES
+   PRIVATE
+      wxwidgets
+)
+
+organize_source( "${TARGET_ROOT}" "" "${SOURCES}" )
+target_sources( ${TARGET} PRIVATE ${SOURCES} )
+target_compile_definitions( ${TARGET} PRIVATE ${DEFINES} )
+target_compile_features( ${TARGET} PRIVATE ${FEATURES} )
+target_compile_options( ${TARGET} PRIVATE ${OPTIONS} )
+target_include_directories( ${TARGET} PRIVATE ${INCLUDES} )
+target_link_libraries( ${TARGET} PRIVATE ${LIBRARIES} )
+