Problem 798. Rotate input square matrix 90 degrees CCW without rot90

Rotate input matrix (which will be square) 90 degrees counter-clockwise without using rot90,flipud,fliplr, or flipdim (or eval).

Example input: [ 1 2 3; 4 5 6; 7 8 9]

Example output: [ 3 6 9; 2 5 8; 1 4 7]

Because of simplistic regexp tests (sorry), you shouldn't use variable names or strings composed of the outlawed function names.