Parse SVG stroke-opacity and fill-opacity

- SVG attribute opacity is now used for object's opacity (instead of fill-opacity)
- fill-opacity and stroke-opacity are added to stroke and fill color values
- Add hsl/hsla support (e.g. hsl(270, 80%, 10%), hsla(320, 10%, 66%, 0.5))
- Add support for rgb/rgba values with whitespaces around values (e.g. rgba( 255 , 100 , 50 , 0.1 )) and percentage values (e.g. rgb(100%, 67%, 15%, 0.8))
- Delete stroke and strokeWidth from fabric.Text (defined in fabric.Object)
- New unit test for parse stroke-opacity and fill-opacity
- Update unit tests (new tests for hsl/hsla and rgb/rgba (whitespaces and percentage values))
- Change equal and deepEqual parameter order (e.g. equal(actualValue, expectedValue, message))
- Doc additions