gitweb: Route rest of action subroutines through %actions

gitweb: Route rest of action subroutines through %actions

Route rest of action subroutines, namely git_project_list and git_opml
(both of which doesn't need $project) through %actions hash.

This has disadvantage that all parameters are read and validated;
earlier git_opml was called as soon as $action was parsed and
validated, git_project_list was called as soon as $project was parsed
and validated.  This has advantage that all action dispatch is grouped
in one place.

Signed-off-by: Jakub Narebski <redacted>
Signed-off-by: Junio C Hamano <redacted>