git: implement diff manifest method
This makes 'hg diff' work.
#!/usr/bin/env pythonfrom__future__importabsolute_import,print_functionimporterrnoimportosimportsysforfinsys.argv[1:]:try:print(f,'->',os.readlink(f))exceptOSErroraserr:iferr.errno!=errno.EINVAL:raiseprint(f,'->',f,'not a symlink')sys.exit(0)