Villainous Horde Manager

* Major breaking change to the structure of the format of the JSON, see the github for more details
* Adds in the concept of waves, allowing for, well, waves of enemies to appear instead of one set of enemies and done.
  * Waves have most of the concepts the horde once had in them, such as how many enemies need to be killed, how many can be spawned at once, etc.
  * As such, each wave in a single horde can play entirely differently!
* Adds in an optional boss phase for each wave
  * If boss entities are included, when the life count is depleted in a wave, and alternate boss bar also defined in the config will be displayed, and the wave will only end when the determined boss entities are killed
  * Depending on configuration, the normal horde can either continue to spawn, or not during the boss phase. 
* Hordes are loaded from a subfolder in the config folder now, again see the github for details
  * But, this means if you keep every horde in its own file, and one file breaks, every other horde should work fine.