annotate/blame tests updates.

annotate/blame tests updates.

This rewrites the result check code a bit.  The earlier one
using awk was splitting columns at any whitespace, which
confused lines attributed incorrectly to the merge made by the
default author "A U Thor <author@example.com>" with lines
attributed to author "A".

The latest test by Ryan to add the "starting from older commit"
test is also included, with another older commit test.

Signed-off-by: Junio C Hamano <junkio@cox.net>