Removed const from the NSInteger return and arg types for calcFrameInterval within SceneViewControllerForCG.

This really isn't needed unless this were a pointer or a reference pass.
Consistified indent and blank-line spacing.

Inconsistency bothers me.  A lot.

• All tab-indentation now.
• Blank lines given the same indentation as the rest of the block.
• Three blank lines between each major block in a file (@interface, @implementation, file-scope constants, includes/forward declarations), with the exception of the first (almost always includes/forward declarations, separated from the file header comment above by 1 blank line).
Fixed a couple of static code analyzer issues.

Both in SceneViewController:
• I was retaining and releasing displayLink more than necessary.  Now autoreleases into the retained property, and just nils the property on deconstruction.
• frameInterval could've been 0 within framesPerSecond, and could've lead to a divide-by-zero error (although I thought I saw this displayed as “NaN”.  Now returns 0 in this case.