Update draft release notes to 1.7.10
Update draft release notes to 1.7.10

Document bunch of bugfix topics to be merged down to 'maint' soonish
for 1.7.9.1 maintenance release.

Signed-off-by: Junio C Hamano <a6723cc3f76163bf7adb636a73ac3b0ceb3e6b9b@pobox.com>

destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git