Working fix for unsigned int conversions
Convert print statement to warning
All uint tests now working
missing colon
parametrize test and other minor changes
Also parametrize uint image tests
fully parametrize uint tests
Fix different hdu number in compressed files.  Also, closes #362 and closes #880
Disable test of 64-bit compressed image
add placeholder for uint parameter
A bit of formatting cleanup, and also added a test to ensure that uint=False does not result in implicit conversion of column data to unsigned ints (which currently fails).  For now uint will be a boolean value that applies to the entire file, but later we can easily make it more fine-grained.
Seems to get support for the uint parameter basically working on table columns (note the test as I originally wrote it was wrong: With uint=False the bzero parameter still causes the data to be converted to float and rescaled).