Merge branch 'jn/web' (early part)
* 'jn/web' (early part):
gitweb: Add "next" link to commit view
gitweb: Add title attribute to ref marker with full ref name
gitweb: Do not show difftree for merges in "commit" view
gitweb: SHA-1 in commit log message links to "object" view
gitweb: Hyperlink target of symbolic link in "tree" view (if possible)
gitweb: Add generic git_object subroutine to display object of any type
gitweb: Show target of symbolic link in "tree" view
gitweb: Don't use Content-Encoding: header in git_snapshot