Make version generation more sane for program

GenerateVersion.cmake

@@ -0,0 +1,26 @@
+find_package(Git)
+
+if(GIT_EXECUTABLE)
+  get_filename_component(WORKING_DIR ${SRC} DIRECTORY)
+  execute_process(
+    COMMAND ${GIT_EXECUTABLE} describe --always --dirty
+    WORKING_DIRECTORY ${WORKING_DIR}
+    OUTPUT_VARIABLE PROGRAM_GIT_VERSION
+    RESULT_VARIABLE ERROR_CODE
+    OUTPUT_STRIP_TRAILING_WHITESPACE
+    )
+
+  if(NOT ERROR_CODE EQUAL "0")
+    set(PROGRAM_GIT_VERSION "")
+  endif()
+
+endif()
+
+if(PROGRAM_GIT_VERSION STREQUAL "")
+  set(PROGRAM_GIT_VERSION 0.0.0-unknown)
+  message(WARNING "Failed to determine version from Git tags. Using default version \"${PROGRAM_GIT_VERSION}\".")
+else()
+message("Git Version: \"${PROGRAM_GIT_VERSION}\".")
+endif()
+
+configure_file(${SRC} ${DST} @ONLY)