Initial support for gradient fills
TODO: tests and python bindings
TODO: data defined settings
TODO: gradient only color ramp combo option
Allow setting start/end points for gradient fills
Add support for rotation of gradient fills
Clean code
Start work on data defined gradients
More work on data defined gradients
Fix build, saving of color ramps
Restrict color ramp choices to gradient only
Start tests for gradients
Clean code
Test suite for gradients pt 1
Finish test suite
Make code nicer by using enums instead of ints and QGradient specific enums