Fix ColorHistogram to work with Open File
Add coverall support
Execute coveralls without flags.
Change to test directory before running coveralls
Ignore setup. No need for tmp dir any longer.
Fix invocation of nosetests.
Merge pull request #819 from stefanv/coverall_support

Add coveralls support
Merge pull request #804 from tonysyu/viewer-color-hist-fix

Fix ColorHistogram to work with Open File
Merge pull request #822 from JDWarner/fix_freeimage_metadata_test

FIX: New versions of FreeImage report software as "I", not "ImageMagick ..."
FIX: Specify field index for Python 2.6 compatible use of str.format()