Fix index page for Internet Explorer

This page stinks anyway.
Work-around for lack of video texture support in Internet Explorer #68
Optimize enum validator
Re-factor input set-up and validation in preparation for #40
Better/more unit tests for blocking reserved names
- Effect inputs
- Transform inputs
- Aliases
Transform `.inputs()` no longer reports methods
Fix mirror image example link; use robot instead
Fix case-insensitive enum validation
Validate Transform Node inputs #40, with unit tests
Bug Fix: Secondary WebGL target was failing to render
Clean junk out of chroma key shader
Retain `id` property on destroyed nodes
Bug Fix: target `.input` is now a method, not a property.
- Matches other node types.
- unit test updated
Bug fix: One unit test was not cleaning up after itself
Added utility methods to Seriously for detecting whether an object is a node of any given type
- isNode
- isEffect
- isSource]
- isTarget
- isTransform
- Added unit tests for all of the above
Bug fix: Blur was not rendering when amount <= 0.1
- Also cleaned unused junk out of shaders
Bug Fix: Secondary WebGL targets were rendering at wrong size/aspect if placed after a transform
Fixed texture shape/size in mirror effect
Fixed undeclared variable in index.html
Remove branching from split shader #69