Support Video Assets

[kalegd]

We should support Video assets in Digital Bacon

Some things to think about

• Video assets will work largely like Image assets in that they can be loaded into using default parameters directly from the Video Assets Menu UI in the Library, or as part of a Texture
• We'll need a new VideoTexture and TextureTypes.VIDEO enum value
• Many asset parameters that filter only TextureTypes.BASIC will need to be updated to support both BASIC and VIDEO
• TextureInput needs to be updated to support a list as the filter

[kalegd]

I'm going to include VideoAssets in 0.2.1, but leave VideoTextures and the required changes for that for 0.2.2 0.3.2