Fixed problem with inverted image rendering

Problem was when image is inverted it produces floats not ints. Changed
reDraw() function to cast to floats. Means ints get a decimal point and
zero, but floats are unchanged.
Merge pull request #8 from ciaranmooney/FixColourMap(floats)

Fixed problem with inverted image rendering
Fixed memory leak

There was a major memory leak in pbinversion.cpp file, polar_b(...)
routine, which is fixed now.
Other small changes do not affect functionality.
Forgot to remove debugging code
Silly commit
Merge remote-tracking branch 'upstream/master'