Break scene.transforms into subpackage
Rename Transform => BaseTransform
Fix unit test
Added note about basetransform - chaintransform cyclic import
Make transform imports explicit
flakify
Add scene.transforms to setup.py
Modified ModularVisual to check dimension of color, added reactive polygon test and added color to visuals and examples

Minor fix post rebase

Fixed spelling mistake

Added reactive ellipse tests
Implement (partly) proper way to inherit from Entity

That is, each Subclass does `__init__(what=None, I=3, need=3, **kwargs)`
and then `SuperClass.__init__(self, **kwargs)`

Also fixes to Text class and SceneCanvas can be other bgcolor than
black :)
Changed coordinates of test visuals
Added reactive regular polygon tests
Fixed  regular polygon tests
Merge pull request #377 from lcampagn/transforms-subpackage

Break scene.transforms into subpackage
Address reviewer comments

I incorporated changes from #358, so that when that PR gets
rebased, it should result in minimal clashes.
flakify
Adds egl API

It is not 100% complete and the code to load the lib should
be generalized, but this should be a good starting point.
I had a working demo with this some time ago.
Make ipynb_vnc not tested
Merge pull request #381 from almarklein/lib-egl

Adds egl API
address comments
Merge pull request #378 from almarklein/entity-inheritance

Implement (partly) proper way to inherit from Entity