BUG: PyQt4 compatibility
added checkbox to auto normalize the image to between 5% and 95%
significant additions:
1. added a combobox to provide multiple image intensity display options
2. added spinboxes to provide interactive manipulation of the image intensity
3. added code to prevent the max_intensity spinbox being less than the min_intensity spinbox and vice-versa
3a. this code is rather slow in its execution, a more rapid version would be nice. I ran into issues with trying to compare the values of floats
FUNC: added clumsy workaround to enable more decimal precision to be displayed in the intensity step spin box
minor commenting
BUG: missed an underscore in front of an instance variable
formatting.  commented a print line and added parentheses around a return pair
cleaned up formatting
more code cleanup
renamed some UI variable elements
reformatted comments
added button + 2 combo boxes to swap axes
fixed missing underscore in update_colormap method
remove storage of min/max intensities from __int__
added code to change the dimensions of the main axes and horiz/vert axes depending on the dimensions of the new image passed in update_image method but commented them due to display bug
code cleanup: 	removed unused method compute_decimals_to_show
		removed backslash due to caswell_rage
bug fix:	added test for intensity_step being zero to remove div_by_zero error
		set default number of decimals to display to be 2
		set default intensity step to be 0.01 for no better reason than some number had to be picked
disabled button to swap axes
bug: 		swap_stack_axes was not managing the array indexing properly
comment: 	added doc for swap_stack_axes
added a blank line
DOC:
fixed docstrings in the set_min_limit and set_max_limit methods
fixed new style connect notation (no actual change as far as i can tell)
updated the connect call for the color map combo box to the new style
(no actual changes as far as i can tell)