Update to 1.7.9.1
    
    Use git-core.googlecode.com for source URL, as that's where Junio is
    posting official tarballs now.  The gpg signatures are now available on
    that site in the comments for each tarball.  For example, the signature
    for 1.7.9.1 and download link can be found at:
    
    http://code.google.com/p/git-core/downloads/detail?name=git-1.7.9.1.tar.gz&can=2&q=