Add date and git revision to non-release package names

CMakeModules/CMakeVersionSource.cmake

@@ -0,0 +1,37 @@
+# Try to identify the current development source version.
+set(CMAKE_VERSION_SOURCE "")
+if(EXISTS ${CMAKE_SOURCE_DIR}/.git/HEAD)
+  find_program(GIT_EXECUTABLE NAMES git git.cmd)
+  mark_as_advanced(GIT_EXECUTABLE)
+  if(GIT_EXECUTABLE)
+    execute_process(
+      COMMAND ${GIT_EXECUTABLE} rev-parse --verify -q --short=4 HEAD
+      OUTPUT_VARIABLE head
+      OUTPUT_STRIP_TRAILING_WHITESPACE
+      WORKING_DIRECTORY ${CMAKE_SOURCE_DIR}
+      )
+    if(head)
+      set(CMAKE_VERSION_SOURCE "g${head}")
+      execute_process(
+        COMMAND ${GIT_EXECUTABLE} update-index -q --refresh
+        WORKING_DIRECTORY ${CMAKE_SOURCE_DIR}
+        )
+      execute_process(
+        COMMAND ${GIT_EXECUTABLE} diff-index --name-only HEAD --
+        OUTPUT_VARIABLE dirty
+        OUTPUT_STRIP_TRAILING_WHITESPACE
+        WORKING_DIRECTORY ${CMAKE_SOURCE_DIR}
+        )
+      if(dirty)
+        set(CMAKE_VERSION_SOURCE "${CMAKE_VERSION_SOURCE}-dirty")
+      endif()
+    endif()
+  endif()
+elseif(EXISTS ${CMAKE_SOURCE_DIR}/CVS/Repository)
+  file(READ ${CMAKE_SOURCE_DIR}/CVS/Repository repo)
+  set(branch "")
+  if("${repo}" MATCHES "\\.git/")
+    string(REGEX REPLACE ".*\\.git/([^\r\n]*).*" "-\\1" branch "${repo}")
+  endif()
+  set(CMAKE_VERSION_SOURCE "cvs${branch}")
+endif()