Refactoring.
- Replaced old application initialization with a new, cleaner one
- Heavily modified cache/database subsystem to use mybatis as the
  "get me the object from database" system, while retaining computing
  cache
- Modified code formatting settings
- Added secondary thread pool that could be used for parallelizable tasks
  in processors (like fetching tweets from multiple accounts in multiple
  threads)
- Removed protobuf interface - it was too annoying to support at this
  stage of this project