Merge pull request #25 from nebula2d/development

Merge pull request #24 from nebula2d/master
Merge pull request #27 from jonbonazza/master

cleanup and avocado (script editor) module addition
Merge pull request #28 from jonbonazza/master

behavior implementation in editor
Merge pull request #29 from nebula2d/development

Development
Merge pull request #30 from jonbonazza/master

rendering enhancements in editor and update/render stag modifications in core
Merge pull request #31 from nebula2d/development

Development
Merge pull request #33 from jonbonazza/master

save/open project and bug fixes
Merge pull request #34 from nebula2d/development

Development
Merge pull request #36 from jonbonazza/master

Physics in core
Merge pull request #37 from nebula2d/development

Development
Merge pull request #38 from jonbonazza/master

added methods for manipulating forces of RigidBodies.
Merge pull request #39 from nebula2d/development

Development
Merge pull request #42 from jonbonazza/master

bug fixes
Merge pull request #43 from nebula2d/development

Development
Merge branch 'master' of https://github.com/nebula2d/nebula2d
New scenes can be created from editor