Log Message:
Update to 2.9:

1. Mercurial 2.9 (2014-02-01)

This is a regularly-scheduled feature release.
    aliases: make "_checkshellalias()" invoke "findcmd()" \ 
with "strict=True"
    backout: add a message after backout that need manual commit
    backout: avoid update on simple case
    bash_completion: add completion for deleting a shelve
    bash_completion: add global support for -B|--bookmark
    bash_completion: add global support for -b|--branch
    bisect: --command without --noupdate should flag the parent rev it tested
    bookmarks: allow push -B to create a new remote head (issue2372)
    branchmap: cache open/closed branch head information
    cat: increase perf when catting single files
    changectx: increase perf of walk function
    clone: do not turn hidden changeset public on publishing clone (issue3935)
    convert: use branchmap to change default branch in destination (issue3469)
    date: allow %z in format (issue4040)
    diff: search beyond ancestor when detecting renames
    hgweb: infinite scroll support for coal, gitweb, and monoblue styles
    merge: consider successor changesets for a bare update
    patch: add support for git delta hunks
    phase: properly compute ancestors of --rev on push (issue3786)
    rebase: abort cleanly when we encounter a damaged rebasestate (issue4155)
    rebase: do not crash in panic when cwd disapear in the process (issue4121)
    record: --user/-u now works with record when ui.username not set (issue3857)
    record: re-enable whitespace-ignoring options
    relink: abort earlier when on different devices (issue3916)
    strip: add faster revlog strip computation
    subrepo: check phase of state in each subrepositories before committing
    subrepo: make it possible to update to hidden subrepo revisions
    subsettable: move from repoview to branchmap, the only place it's used
    templater: selecting a style with no templates does not crash (issue4140)
    update: consider successor changesets when moving active bookmark
    url: added authuri when login information is requested (issue3209)