Git 1.7.7.7, 1.7.8.6 and 1.7.9.7

New releases for the three older maintenance tracks have been tagged and tarballs uploaded. They were mostly to push out small documentation fixes that have already been in the 'master' branch for the next feature release, except for v1.7.9.7, which has a fix for performance regression in "git fetch" introduced some time ago where the command wastes cycles to verify the connectivity of objects received from the other end, being unnecessarily pessimistic.