Add git_header_div subroutine which prints "header" divs, now with
class "header" (class "title" is taken, and has set CSS style,
changing appereance and maing layout wrong), and use it thorough
gitweb.cgi.  Change header linking to project summary from empty
(  as a contents of link) to having $project as contents/name
of link.  Sometimes a little reordering.
Signed-off-by: NJakub Narebski <jnareb@gmail.com>
Signed-off-by: NJunio C Hamano <junkio@cox.net>