Updated to upstream commit c2310a8bf3601a68c676465acd6e52603f85eb8e
    
    - Change manpage repository address to github.
    - Fix Makefile `make man` to work w/o .git
    - Correct splitting of git-ls-tree output
    - Add missing alt text for img.
    - Move </tr> to right place.
    - Use id-based fragment identifiers.
    - Generate html5, not xhtml.
    - Add missing xhtml end tag.
    - Added HTML header meta tag so that author names will be shown correctly also when the file is opened in a browser.
    - Removed useless merge_authors configuration option. Use .mailmap instead.
    - How to merge author information.
    - Document start_date option on the manpage.
    - implement a way to limit the statistics to commits after a start date
    - properly terminate created subprocesses
    - Fix indentation to be consistent.
    - Go back to previous dir to no fail on relative paths
    - Bump copyright year.
    - Y-Axis of graphs start at zero
    - fix: let "Pool" for line count data collection honor "processes" configuration setting
    - Bump README python requirement to 2.6.0.
    - Remove backticks from author names passed to gnuplot.
    - Fix minor documentation issues
    - Make number of processes configurable.
    - Fix performance issue for huge repositories
    - Bump copyright year.
    - Refer to manual page in usage.