refactor and start of multi-threading

- Moved some of the lua code around and deleted a few now-unused files

- Updated flowHub to be a single-file entry point for the various sections
  of the program. Has functions to start the launcher, game, etc.

- Started implementing multi-threading in the c++ code in order to better
  handle the data communication with the server and to eventually handle
  other functions such as sounds within the game.