[FIX] Fixed sweepflag bug in some operators
fixed isposintscalar to spot internal for MATLAB > 2011B
[ADD] Added unsupported data type warning in mtimes
reverted warning for distributed in mtimes; add again after April 2013 software release
[ADD] Expanded mtimes to support oppFoG
[FIX] Merged conflicting comments in mtimes
[ADD] Cleaned up and updated TODO list
[FIX] Fixed TODO formatting
[ADD] Added opNull and tests