tools (utils): better repository version handling: - removed save_dir_path and .hg_data/pickle method: it is not needed to save repository data anymore as its version is now saved on installation by setuptools_scm - added "distance" (number of commits since last tag) - use twisted's which method to find the hg executable - result is now cached on first execution - fixed dirstate method - at last resort, try to find the repository version using the package version, as it is saved there by setuptools_scm