Merge branch 'modularisation'

* modularisation:
  Slowing enemy explosion.
  Fixing bug caused by playing impacting enemy.
  Adding death rending to enemy.
  Reducting turn limit to 25 (this needs fine tuning).
  Adding death ticks and adding kill command to player.
  Moving controls to engine/ControlInterface
  Adding a kill method to the enemy.
  Slowing player.
  Limiting enemy turn speed.
  Adding simple collision detection to enemies. Currently, this fires a warning. Explosions need to be added :).
  Moving pause message to the hud as that is it's logical location.
  Moving spawn entities into the calculation schedule.
  Moving hud rendering into a module.
  Removing level set, as it's now handled by the setData method.
  Moving data object in player.
  Randomising the spawning of enemy entities.
  Renaming "_populateArena" to "_spawnEntities".
  Removing existing explosions. Explosions will be handled by the entity in future.
  Layering clouds.
  Moving player existance information into player object.
separated out the enemyFactory detection methods from repositioning.

This still needs a little work to make it more efficient.
Adding basic player explosion.

This and the enemy explosion need adding to the constants.
Removing last call to embeded helpers.
Removing embeded helpers.
Removing explosion renderer.
Removing boss renderer.
Migrating missed internal helper calls to helper module.
Adding basic prop factory.
Merge branch 'master' into gh-pages

* master:
  Adding basic prop factory.
  Migrating missed internal helper calls to helper module.
  Removing boss renderer.
  Removing explosion renderer.
  Removing embeded helpers.
  Removing last call to embeded helpers.
  Adding basic player explosion.
  separated out the enemyFactory detection methods from repositioning.