Merge pull request #6 from square/add-hidpi-only-mode

Rearrange readme sections

adds apropos-image-width function for hidpi-only mode utility purposes

Test against more rubies

Add hidpi only mode

Merge pull request #8 from ghepting/gary/add-height-to-base-variants

adds support for generating height on class variants

Merge pull request #7 from square/gary/fix-breakpoints-bug

Fix substring matching on literal extensions

Version 0.1.3

Merge pull request #5 from square/sass-str-index-bug

Fix changed behavior of str-index in Sass 3.3

Merge pull request #3 from square/gabriel/fix-specs-for-compass-1-0

Update references to Compass config for 1.0

Update rubies for Travis