BGE: Added getActionName() function to KX_GameObject()

It works similar to getActionFrame(), you have to give a layer or not (for layer 0) as the argument and it returns the name of the animation that the object is currently playing.

Example:

```
import bge
own = bge.logic.getCurrentController().owner
own.playAction("SomeAction",0,20)
print(own.getActionName())
```
>> SomeAction

Here is an example file, just open the blend file with the terminal opened
and press P, you can see how the current animation is being printed:
{F217484}

Reviewers: moguri, hg1, panzergame, campbellbarton

Reviewed By: panzergame

Subscribers: campbellbarton, hg1, #game_engine

Projects: #game_engine

Differential Revision: https://developer.blender.org/D1443