a first take at image size binning
add tests on getBinnedDimension
style
explicitly produce square bounding boxes, test the resize method
implement width-only binning behaviour as discussed with Shawn, change tests to reflect this.
correct for style
add built files
Merge remote-tracking branch 'origin/v2.0' into v2.0-image-binning

Conflicts:
	build/mobify.min.js

Also brought back some tests in the Gruntfile
change target bins, update tests to reflect this.
fresh built files
Merge pull request #215 from mobify/v2.0-image-binning

image size binning