uses package_targets for package steps WIP
makes cloning of tools use hg not hgtool. adds rev to all src clones
finishes uses package_targets for package steps
mvs peri clobber and old pkgs to default config, renames ccache, fin win32 remainin c items
makes pre config lock see build variant and comments on it. switches platform to stage_platform in pre_config
enables enable_post_linker_size for win32 pgo builds