Merge branch 'dmitrijsledkovs/pu' into pu

reach out and touch someone

This shaves 3 seconds off of KDE's config compile time :-)

Yes, I know wrap_print has that extra print statement, but otherwise it
was lying around not earning its keep so I gave it a little side job :-)

security fix for optional ADC (admin-defined command) feature

Thanks to Dylan Simon for catching it...

update CHANGELOG

mirroring support...

conf/example.gitolite.rc
  - "slave mode" flag to disable pushes and "list of slaves"

hooks/common/post-receive.mirrorpush
  - code to push to the mirror, creating the repo if needed

src/mirror-shell
  - shell for master pushing to a slave, because we don't actually want
    to go through gitolite itself, yet we have to take care of
    $REPO_BASE being wherever.  And of course we have to set
    GL_BYPASS_UPDATE_HOOK to 1 for the push to happen!

src/gl-mirror-sync
  - manually runnable program to sync from current server to another