~runxiyu/sjdb#3: Code quality

There are quite a few issues with the code quality that must be resolved:

The use of datetime objects, YYYY-MM-DD strings, and integer date representations are inconsistent.
Some main functions are too long.
Sometimes the API doesn't need to be called at all in weekly.py. Don't request for a token and don't make any network requests if all file downloads have already been completed.
Some variable names are frankly stupid. What does tbll look like to you?
Some things e.g. in menu interpretation are hardcoded.
Configuration objects should probably not be passed around. It makes more sense to directly pass relevant things as variables directly.

Commit eaa922639f10f78d7b0e524557eaeb75f69c90fd fixes most of this for weekly.py.

Date strings should not be passed around. Pass around "aware" datetime objects instead.