Frost improvements

[jackschmidt]

3 efficiency improvements and more specific feedback to user.

• Don't recompile the github regexes for every remote (not a big deal, most repos have few remotes)
• Don't request HEAD to be moved if we are only going to move it back
• Check to see if the tree changed before updating an old publication tag If we do update an old publication tag call it "Update" instead of "Create" to help give better bug reports if the git server rejects the subsequent git push from xake serve.

[kisonecat]

Thanks for this!