Deleted unneeded backend code (in Python)
Merge branch 'master' of https://github.com/mchernyavskaya/mooch-sentinel
Styled popup window
Updated README and project description.
Commit counts only during the current day.
Start using changed settings instantly.

Previously, Mooch had to be restarted after blacklist change.
Fixed README
Use global Mooch instance.
Display label when goal is disabled.
Check if date is okay in single place.

From now on, Mooch object is responsible for deciding whether last commit date
is okay or not. In fact, we can remove `ok` field from status object.
On status change, send a message to update popup.
Changed conditions of periodic status update.

1. Request status for each pending task, even if there are some finished
   tasks already. For example, even though GitHub commits unblock Mooch,
   it will keep request status for CodeForces anyway.

2. Global okTime not needed anymore. We check expiration date of each
   task individually.
Bugfix: status check failed on null dates.
Removed unused global okDate.
Rename codeforces labels.
Apply changes in options immediately after saving.

This includes status refresh so that new login settings could have come
in effect.
Add About page
README update and version bump
Extended default list of time killers