Merge pull request #2 from DarkLotus/master

Added back all your node types
+ When drawing a node mouse Cursor will turn into a preview rectangle.
+ Modified they way the drawPanel CtxMenu is filled.
Todo: Refactoring.
+ Console Output automatic scroll down on new Log event.
+ Average Node
+ Implemented poor implementation for Pondered Average, you need connect the inputs in this specific order: Value_Input -> Value_Weight , Value2_Input -> Value2_Weight, and so on.

+ Fixed a bug with SetValue form which was trying to retun Int type instead of float.
+Execute will now depend on a timer with default 1000ms delay.
* Execute button triggers the timer on/off
* Timer tick event runs the evaluation of the graph.
+ Poor implementation of Hysteresis Node, hit a design wall right now since the past nodes have been all considered to work with float data type and this kind of node should work as a Bool node, either True or False which current implementation doesn't allow since Process() returns float and Value is set as float too...
+ TestDevice  Node just to generate random input numbers instead of having a Constant.