New: There should be a pre-defined macro specifying the latest git commit id (GIT_COMMIT_ID)

[ravi688]

git_commit_id = run_command('git', 'rev-parse', 'HEAD', check : true).stdout().strip()

defines = [
  '-DGIT_COMMIT_ID="' + git_commit_id + '"',
  '-DBUILDMASTER_VERSION_MAJOR=' + meson.project_version().split('.')[0],
  '-DBUILDMASTER_VERSION_MINOR=' + meson.project_version().split('.')[1],
  '-DBUILDMASTER_VERSION_MICRO=' + meson.project_version().split('.')[2], 
  '-DMESON_BUILD_TEMPLATE_PATH="' + join_paths(meson_build_template_install_dir, 'meson.build.template') + '"'
]