[PATCH] control/limit output of git-rev-list

gitweb.cgi's default view is the log of the last day and git-rev-list
can stop crawling the whole repo if we have all our data to display in the
browser. Also the rss-feed query needs only the last 20 items. This
will speeds up these queries dramatically.

usage: rev-list [OPTION] commit-id
--max-count=nr
--max-age=epoch
--min-age=epoch

Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>