git-gui: Improve our labeling of blame annotation types
It feels wrong to call the -M -C -C annotations "move/copy tracking" as they are actually the original locations. So I'm relabeling the status bar to show "copy/move tracking annotations" for the current file (no -M -C -C) as that set of annotations tells us who put the hunk here (who moved/copied it). I'm now calling the -M -C -C pass "original location annotations" as that's what we're really digging for.
I also tried to clarify some of the text in the hover tooltip.
Signed-off-by: Shawn O. Pearce <firstname.lastname@example.org>