first step at moving Button to controls
merge in style refactor
first step at using QtQuick control's Button instead of a base Item.  This will give us the integration with accessability, button groups and actions.
Merge branch 'master' of https://github.com/quantum-os/qml-material into use_controls_for_button

Conflicts:
	modules/Material/Button.qml
use new theme configs
Merge branch 'master' of https://github.com/quantum-os/qml-material into use_controls_for_button
set default elevation
sync travis file from extras_refactor
Merge branch 'master' of https://github.com/quantum-os/qml-material into use_controls_for_button

Conflicts:
	.travis.yml
Change elevation and background colors to match Material spec.
Merge pull request #32 from geiseri/use_controls_for_button

Use Qt Controls as the base for Button