BGE: Change character jumping to char

* Change the character jumping variables and methods from int to char.
* Limit the maxJumps integer value from 0 to 255.
* Allow to set the minimum jump amount to 0.

Reviewers: panzergame, lordloki, moguri

Reviewed By: lordloki, moguri

Subscribers: agoose77

Projects: #game_engine

Differential Revision: https://developer.blender.org/D1305

doc/python_api/rst/bge_types/bge.types.KX_CharacterWrapper.rst

@@ -25,7 +25,7 @@ base class --- :class:`PyObjectPlus`
 
       The maximum number of jumps a character can perform before having to touch the ground. By default this is set to 1. 2 allows for a double jump, etc.
 
-      :type: int
+      :type: int in [0, 255], default 1
 
    .. attribute:: jumpCount