gitweb: Add "next" link to commitdiff view
Add a kind of "next" view in the bottom part of navigation bar for
"commitdiff" view.
For commitdiff between two commits:
(from: _commit_)
For commitdiff for one single parent commit:
(parent: _commit_)
For commitdiff for one merge commit
(merge: _commit_ _commit_ ...)
For commitdiff for root (parentless) commit
(initial)
where _link_ denotes hyperlink. SHA1 is shortened to 7 characters on
display, everything is perhaps unnecessary esc_html on display.
Signed-off-by: Jakub Narebski <jnareb@gmail.com>
Signed-off-by: Junio C Hamano <junkio@cox.net>