gitweb: Change appereance of marker of refs pointing to given object

gitweb: Change appereance of marker of refs pointing to given object

Change git_get_references to include type of ref in the %refs value, which
means putting everything after 'refs/' as a ref name, not only last
part of the name.  Instead of separating refs pointing to the same
object by " / " separator, use anonymous array reference to store all
refs pointing to given object.

Use 'git-ls-remote .' if $projectroot/$project/info/refs does not
exist.  (Perhaps it should be used always.)

Refs are now in separate span elements.  Class is dependent on the ref
type: currently known classes are 'tag', 'head', 'remote', and 'ref'
(last one for HEAD and other refs in the main directory).  There is
encompassing span element of class refs, just in case of unknown ref
type.

This might be considered cleaner separating of git_get_references into
filling %refs hash only, and not taking part in formatting ref marker.

Signed-off-by: Jakub Narebski <jnareb@gmail.com>
Signed-off-by: Junio C Hamano <junkio@cox.net>