Log Message:
Update to 1.7.2:

This is a scheduled bugfix release.

    * checknlink: return False if .hgtmp file preexists (issue2517)
    * commit: search both parents for missing copy revision (issue2484)
    * context: walk both parents for workingctx.ancestors()
    * convert/svn: fix changed files list upon directory replacements
    * hgwebdir: fix incorrect index generation for invalid paths (issue2023)
    * keyword: copy: when copied source is a symlink, follow it
    * mq: ignore subrepos (issue2499)
    * rebase: support --detach when null is common ancestor
    * subrepo: fix removing read-only svn files on Windows
    * subrepo: handle missing subrepo spec file as removed
    * subrepo: prune empty directories when removing svn subrepo
    * subrepo: use subprocess directly to avoid python 2.6 bug
    * util: do not crash on revisions with negative timestamp (issue2513)
    * util: do not recurse in makedirs if name is '' (issue2528)
    * win32mbcs: use extsetup() to wrap functions only once
    * wix: add support for x64 native MSI packages