Revert particle engine changes.

This reverts the following commits:

- 8fd3ead Fixed particle editor with ParticleEmitter bounds
- c317487 Fixed examples for ParticleEmitter bounds
- dc7ab39 Fixed a bug in getRandomPoint function
- b31c226 Fixed ParticleEmitter Bounds
Fixed the drag behavior of the particles editor
Fixed the drag behavior of particle emitters
Redo particle engine changes.

This reverts commit fbbc582cfd698f243db8e241f4ef52ea0fa419d4.
Merge pull request #505 from aaschmitz/1.0.x

Fixed issue with the drag-points on the particle editor
Redo particle engine changes.

This reverts commit 1519fbbe4216ef508e8147fa5268a01463db118f.
Merge branch '1.0.x'