Blender Git Loki

Changed behavior of how pattern is controlling by mouse:

- Removed scaling option which used to be Ctrl+Slide of individual
pattern corner.
- Added extra rectangle area which is being drawing around pattern
and which supports the following things:

* Slide by it's left upper corner would define offset of marker
* Slide by it's right bottom corner would scale overall pattern

- Added extra handle which is drawing from pattern center and which
is being used to define scale and rotation of pattern area.