fabric.StaticCanvas.clear() delete _activeObject

If canvas is cleared ```canvas._activeObject``` should be removed.
Merge pull request #513 from Kienz/patch-1

Delete _activeObject in `fabric.StaticCanvas.clear()`
Include pathOffset in fabric.Path.toObject()

Include pathOffset in toObject() of fabric.Path and use it (if defined) in _initializePath().
This should fix issue #500.
Merge pull request #515 from Kienz/patch-2

Include pathOffset in fabric.Path.toObject()
Mention that `set` doesn't update border/control and that `setCoords` should be called for that. Closes #518.
Only transform rect when part of path group not group. Closes #495
Build distribution. Version 1.1.5.
[BACK_INCOMPAT] fabric.Object.setActive(…) -> fabric.Object.set('active', …). fabric.Object.isActive is gone (use `active` instead)
Add lastsemic option to jshint
Fix pixelate filter. Thanks @Oleg. Closes #523
Group fixes. Closes #504. Closes #505
Cleanup events and gestures modules
Build distribution
Apply sencha patch to excanvas (http://dev.sencha.com/playpen/tm/excanvas-patch/)