(NOT READY) Geometry sample refactor

This is some work in progress on the Geometry sample, though I thought I'd put it up for feedback and a couple questions before I have dinner.

Changes:
* shaders moved to assets folder, reload them now by hitting return
* works on iOS. Double tap screen to change geoms.
* using geom::VertexNormalLines instead of the custom DebugMesh to draw normals. This is how I ran into #587 (see in line note).
* Some cleanup and updates for changes to cinder/ glNext since this was originally written.

Question: the stripes.jpg is loaded and bound, but isn't actually used for drawing. Do we need this in there, or should it be removed?