Fix various minor issues, try to get coffeestats-cli working again

Hi,

here's a pull request for two minor issues and an attempt at solving an issue that may turn out to quite the issue…

da3cd64 and fd482fb are no-brainers, but I figured I'd just fix them while I was at it anyway.

2ba579c is an attempt to fix `Error: You can not enter dates in the future!` which I currently always see when using my updated version of coffeestats-cli with the new django-based coffeestats.org. The issue might be caused by clock skew between my box and your server (which should be resolved by this commit), or by timezone differences between my box and your server (in which case this pull request will not solve the issue and the view needs to be changed to construct `datetime.now()` with the appropriate time zone).