Added calibration points for x^2, clean up

Added calibration points for square-law detector.  Cleaned up the code
a little.  Also I have decided to just keep using the TDMS format.  My
code now calls the convertTDMS2 function to convert the TDMS to a MAT
file
Added convertTDMS2.m

This is the function used for converting the TDMS lab view file to a
MAT file that matlab can work with.  Function created by several
authors, please see file for revision history and credit to authors
Fixed bugs

Fixed some bugs.