Add "minsrc" target to build tarball

This adds a new target that will build the "minsrc" tarball.

It can be created on any platform now, either from the command
line or from within the Window's and Mac's project files.

The output tarball will be in the build directory.

And it's very easy to update the list of files/directories to
exclude...see scripts/CMakeLists.txt

scripts/CMakeLists.txt

@@ -0,0 +1,56 @@
+
+set( TARGET minsrc )
+set( TARGET_ROOT ${topdir} )
+
+message( STATUS "========== Configuring ${TARGET} ==========" )
+
+def_vars()
+
+# Add regular expressions of files/directories to exclude from the tarball
+#
+# NOTE: Each item will be wrapped with "^" and ".*$"
+list( APPEND EXCLUDES
+   .git
+   .gitattributes
+   .gitignore
+   lib-src/expat
+   lib-src/libid3tag
+   lib-src/libmad
+   lib-src/libogg
+   lib-src/libscorealign
+   lib-src/portaudio-v19/bindings
+   lib-src/portaudio-v19/doc
+   lib-src/portaudio-v19/testcvs
+   lib-src/portmidi/pm_csharp
+   lib-src/portmidi/pm_dylib
+   lib-src/portmidi/pm_java
+   lib-src/portmidi/pm_mingw
+   lib-src/portmidi/pm_python
+   lib-src/portmidi/pm_qt
+   lib-src/portmidi/pm_test
+   lib-src/portmidi/portmidi_cdt.zip
+   lib-src/soundtouch
+   lib-src/libvorbis
+   mac
+   plug-ins/analyze.ny
+   plug-ins/fadein.ny
+   plug-ins/fadeout.ny
+   plug-ins/undcbias.ny
+   qa
+   scripts
+   tests/ProjectCheckTests
+   todo.txt
+   win
+)
+
+set( TARBALL "${PROJECT_BINARY_DIR}/audacity-minsrc-${AUDACITY_DIST_VERSION}${AUDACITY_SUFFIX}.tar.xz" )
+   
+add_custom_target( ${TARGET}
+   COMMAND
+      ${CMAKE_COMMAND} -D GIT_EXECUTABLE="${GIT_EXECUTABLE}"
+                       -D TARGET_ROOT="${TARGET_ROOT}"
+                       -D EXCLUDES="${EXCLUDES}"
+                       -D TARBALL="${TARBALL}"
+                       -P "${_SRCDIR}/maketarball.cmake"
+)
+

scripts/maketarball.cmake

@@ -0,0 +1,57 @@
+
+set( TARGET minsrc )
+
+# list command no longer ignores empty elements.
+cmake_policy( SET CMP0007 NEW )
+
+# Check to make sure the source tree has no uncommitted changes
+execute_process(
+   COMMAND
+      ${GIT_EXECUTABLE} status -s --untracked-files=no
+   WORKING_DIRECTORY
+      ${TARGET_ROOT}
+   OUTPUT_VARIABLE
+      output
+)
+
+if( output )
+#   message( FATAL_ERROR "You have uncommited changes\n${output}" )
+endif()
+
+# Get the list of files in the repo
+execute_process(
+   COMMAND
+      ${GIT_EXECUTABLE} ls-tree -r --name-only HEAD ${TARGET_ROOT}
+   WORKING_DIRECTORY
+      ${TARGET_ROOT}
+   OUTPUT_VARIABLE
+      output
+)
+
+# Convert the output to a list
+string( REPLACE "\n" ";" output "${output}" )
+
+# Convert excludes to regular expressions
+string( REPLACE " " ".*$|^" EXCLUDES "${EXCLUDES}" )
+
+# Remove unwanted files from the list
+list( FILTER output EXCLUDE REGEX "^${EXCLUDES}.*$" )
+
+message( STATUS "Creating the minsrc archive at:" )
+message( STATUS )
+message( STATUS "  ${TARBALL}" )
+message( STATUS )
+
+# Write the list to a file to circumvent command line length limits
+set( filelist "${CMAKE_CURRENT_BINARY_DIR}/filelist" )
+string( REPLACE ";" "\n" output "${output}" )
+file( WRITE "${filelist}" ${output} )
+
+# Create the tarball
+execute_process(
+   COMMAND
+      ${CMAKE_COMMAND} -E tar cfJ ${TARBALL} --files-from=${filelist}
+   WORKING_DIRECTORY
+      ${TARGET_ROOT}
+)
+