Removed unimplemented AppDelegate methods
Removed xib file for MatrixView along with CALayer category

Since they were experimental, and not yet used.
AppDelegate now creates a MainViewController and sets its as root
Cleaned up MatrixElementView protocol, no constant strings required
Created square matrix MVP triad, presenter first
Started implementation of SquareMatrix class.
Began implementation of MatrixElement class

to store individual values within the matrix.