changed demo product name to 'Sparrow Demo'
changed prefix for member variables from "m" to "_" (underscore)

This is now the convention that is recommended by Apple.
added 'SPQuadEffect' and 'SPProgram' and using it for rendering
now rendering TTF text with the desired color instead of tinting the image (for performance reasons)
added 'tinted' property to quads and vertex data objects

Untinted objects can be rendered with a very primitive fragment shader, which is a huge improvement on the iPad 1.
Merge remote-tracking branch 'upstream/master'