Mild code clean-up and modifications.

• AppDelegate sets the `SceneViewController…` as the window's `rootViewController` rather than adding the `SceneViewController…`'s view as a subview manually.
	• Also avoiding unnecessary property accesses and preparing the SceneViewController completely before setting to the property.
• Variables holding GL object names now have a ‘_glObjectName’ suffix instead of ‘GLIdent’.
	» I keep going back an forth on this one; ‘_glHandle’ seems to be the most technical, but “handle” isn't used in their docs.  Either way, the unit qualifier suffix (explicit logical suffix) helps.
	» It's not used anywhere (uncommented-out) right now anyway.
• Removed OpenGLES1 line.  We won't be using 1.
• Enabled baseEffect.colorMaterialEnabled.  Might need this.
• Moved GL_BLEND enable and set the blend function to GL_SRC_ALPHA/GL_ONE_MINUS_SRC_ALPHA from `glkView:drawInRect:` to `setUpGL`.
• Added VerticeData struct with GLKVector3 array and count int to SceneForGLK, for easier passing of created vertex data.
• Created SceneForGLK `createCircleVertices:` method to wrap up circle vertex calculation.
	• Uses arrays of `GLKVector3`s instead of just `GLfloat`s.
	• `_r` unit qualifier suffix is now `_rad`.
	• Returns the data in a VerticeData.
	• Note: Currently freeiing with just `free()` in `drawCircleWithin:forView:`.  This should probably be wrapped up for balance.
• Const'd `sliceCount`; doesn't really matter though.
• Minor comment additions and changes.
Working blue circle

The blue circle drawn by `drawCircleWithin:` is now working and nearly identical to CG rendition (by difference filtering screengrabs even).

Thing that were necessary to fix the ¼-screen white oval:
• `baseEffect.transform.projectionMatrix` and `baseEffect.transform.modelviewMatrix` are used to set the matrices with GLKit, not `glMatrixMode(GL_PROJECTION)` and `glMatrixMode(GL_MODELVIEW)`.  Setting those instead, and saving off the GLKMatrix4 and restoring it rather than `PushMatrix`/`PopMatrix`ing.
	• Now properly setting the size of the projection matrix in `glkView:drawInRect:`.
	• Now setting the modelview matrix to identity (or optionally 0.5-scale to be retina-ignorant) in `glkView:drawInRect:`.
	• Now properly translating (centering) and scaling (for both the circle and its border) the modelview matrix in `drawCircleWithin:`.
• `baseEffect.constantColor` is now set instead of its equivalent, `glColor`. 

Circle border:
• Added kCircleEdgeWidth constant to SceneForCG and SceneForGLK.
• Cloned `createCircleVertices:` to `createCircleVertices:hole:`, which although based on the same logic draws a circle with an inner circle cut out (size determined by the `holeRatio`) by creating a tri strip (effectively a quad strip) with one pair of tris (quad) for each slice.
	» This may be better done with a stencil buffer.  I plan to try this and maintain both implementation, performance testing later on.
	» Border is center-aligned (half outside of the fill, half overdrawing the fill) like CoreGraphics.
	» Has a `sliceCount`, `triCount`, and a `vertexCount` (and related iterators) to keep track of things.
• `drawCircleWithin:forView:` changed to have multiple funky bracketed scopes (for now) in order to get both the fill and border draws working.  This'll be revised soon.

Other improvements:
• Changed sliceCount to 32.  It's fast and looks great (with multisampling, especially).
• Calling `GLKVector3Make()` instead of setting `x`, `y`, and `z` individually.  _It's just cooler._

Other unnecessary, and removed (or commented out):
• The colorMaterialEnabled setting in `setUpGL` isn't needed for this (it's more of a lighting thing).
• The constantColor set in `setUpGL` is redundant (the default is already opaque white) and overridden before any and every draw call happens.
• The glViewport and glScissor calls.  I don't think these belong here, or should be called directly like this.
• `glPushMatrix` and `glPopMatrix` within `glkView:drawInRect:`.  Already mentioned above but worth noting that these are unnecessary in any form because the matrices are set up clean at the beginning of the draw.
• The `prepareToDraw` in `glkView:drawInRect:`.  I had no idea what it did when I put it here.
• An old `@fixme` on the glDrawArrays vertex count argument.

Remaining issues:
• We're still creating and freeing the vertices on every draw call.  Soon to be abstracted away, I hope.