Enabled existing color tests.
Added a color test showing the conversion handling of colors and color variables.
Moved colors test back to todo, as it seems like it may fail at the parse stage.
Coerce color name string to a color in color-names test.
Update color_output test to include more variations, and match the formate preservation in sass 3.4.
Update color names to use 'gray' instead of 'grey'
Added more color output test cases to show libsass divergence.
Move more tests fixed by the libsass color changes
Merge remote-tracking branch 'upstream/master' into feature/colors

Conflicts:
	spec/libsass-todo-tests/libsass/arg-eval/expected_output.css
	spec/libsass-todo-tests/libsass/arg-eval/input.scss
	spec/libsass-todo-tests/libsass/color-names/expected_output.css
	spec/libsass-todo-tests/libsass/color-names/input.scss
	spec/libsass-todo-tests/types/expected_output.css
	spec/libsass-todo-tests/types/input.scss
	spec/libsass/arg-eval/expected_output.css
	spec/libsass/arg-eval/input.scss
	spec/libsass/color-names/expected_output.css
	spec/libsass/color-names/input.scss
	spec/todo/libsass/arg-eval/expected_output.css
	spec/todo/libsass/arg-eval/input.scss
	spec/todo/libsass/color-names/expected_output.css
	spec/todo/libsass/color-names/input.scss
	spec/todo/types/expected_output.css
	spec/todo/types/input.scss
	spec/types/expected_output.css
	spec/types/input.scss
Merge pull request #78 from DealerDotCom/feature/colors

Adding in more tests about colors. From DealerDotCom's feature/colors branch.