Make t8001-annotate and t8002-blame more portable

Make t8001-annotate and t8002-blame more portable

These two tests assume that "sed" will not modify the final line of a
stream if it does not end with a newline character.  The assumption is
not true at least for FreeBSD and Solaris 9.  FreeBSD's "sed" appends
a newline character; "sed" in Solaris 9 even removes the incomplete
final line.  This patch makes the test use perl instead.

Signed-off-by: Dennis Stosberg <dennis@stosberg.net>
Signed-off-by: Junio C Hamano <junkio@cox.net>