git-gui: Remove unused commit_list from blame viewer
git-gui: Remove unused commit_list from blame viewer

This list used to store the commits in the order we received
them in.  I originally was using it to update the colors of
the commit before and the commit after the current commit,
but since that interface concept turned out to be horribly
ugly and has been removed we no longer need this list.

Signed-off-by: Shawn O. Pearce <f01032651c12a22b2103346ba96b3b6b231f9d3c@spearce.org>

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