gamebox CLI made a bit more friendly 

Hey I am not sure how much of this you will like or not so I will explain my reasoning for everything

I have updated the gamebox cli so it has more function and could be easier for beginners here is the interface so far

```
  gamebox d                                # starts the application in debug
  gamebox debug                            # starts the application in debug
  gamebox dist [mac|linux|win|all]         # Build an executable for your app
  gamebox g [actor|behavior|stage]         # Gamebox generator, this will generate templated files for you for quicker development
  gamebox generate [actor|behavior|stage]  # Gamebox generator, this will generate templated files for you for quicker development
  gamebox help [TASK]                      # Describe available tasks or one specific task
  gamebox n PATH                           # Generates a new gamebox game at PATH.
  gamebox new PATH                         # Generates a new gamebox game at PATH.
  gamebox s                                # starts the application
  gamebox start                            # starts the application
```
What was done

* aliased the gamebox script as gb for less typing
* added gamebox start and gamebox debug so that it can be controlled how the users start the app and there can be one uniform way of doing so. This command (as well as all of the others I implemented) refer to the associated rake tasks
* added gamebox dist, this will do the dist rake tasks and has a nice feature to do all 3
* added aliases for most methods for less typing like `gamebox start` can be written as `gb s`
* added generators and templates for actors, stages, and behaviours these can be better extended in the future, like automatically adding the stage to the config
* reorganized the app template so the src file looks like this

```
src
  |__app.rb
  |__actors
  |    |__player_actor.rb
  |__behaviors
  |    |__.gitkeep
  |__stages
       |__demo_stage.rb
```
this allows for cleaner organization 

* Added absolute paths to the gamebox rake file so that generators and starting the game can be invoked anywhere in the project tree of a game 

All tests pass, although I don't see any tests for the CLI so I might have to implement them.

Hope you like it, cheers!