Disable edit links if a task is not locked

Issue #186
Enable logger, expects __name__ not __file__
Rewrote contributors view (faster execution)

Issue #189
Add highlighting tiles marked as done on the map

Issue #199
Show cumulative tile data for each day

Issue #199
Retain TileHistory on tile split

Issue #200
Remove useless get_stats call
Merge pull request #203 from dodobas/master

Fix for a few issues