Log Message:
Update to 2.5.1:

This is a non-scheduled bugfix release.
    hgk: support the old way of getting the current Ttk theme (issue3808)
    hgweb.cgi: fix internal WSGI emulation (issue3804)
    hgweb: make 'summary' work with hidden changesets (issue3810)
    incoming: fix incoming when a local head is remotely filtered (issue3805)
    largefiles: don't crash when trying to find default dest for url without path
    rebase: derive node from target rev (issue3802)