gitweb: Refactor common parts of 'log' and 'shortlog' views
Put the common parts of git_log and git_shortlog into git_log_generic
subroutine: git_log and git_shortlog are now thin wrappers calling
git_log_generic with appropriate arguments.
The unification of code responsible for 'log' and 'shorlog' actions
lead to the following changes in gitweb output
* 'tree' link in page_nav now uses $hash parameter, as was the case
for 'shortlog' but not for 'log'
* 'log' view now respect $hash_parent limiting, like 'shortlog' did
* 'log' view doesn't have special case for empty list anymore, and it
always uses page_header linking to summary view, like 'shortlog'
did.
Signed-off-by: Jakub Narebski <jnareb@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>