forbid username with '\n' at the changelog level It was already forbidden for ui.username() but no verification were made for username passed through the commandline.

listdir: add support for aborting if a certain path is found This lets us bail out early if we find '.hg', letting us skip sorting and bisecting for it.

osutil: fix some braindamage - entkind returns -1 on failure - compile if AT_SYMLINK_NOFOLLOW is missing - avoid fullpath overflow