Copy gitstats.css to output path if it does not exist.
treeccd37814f1c9e76f7e4a502eba3bbb6a8fc1e866
-rw-r--r-- 119 commits_by_year.plot
-rw-r--r-- 187 commits_by_year_month.plot
-rw-r--r-- 150 day_of_week.plot
drwxr-xr-x - doc
-rwxr-xr-x 23520 gitstats
-rw-r--r-- 1067 gitstats.css