GL spike shows something, but out of scene graph.
Gives access to native window handle

A uintptr is used for the handle type, in counterpart to WId which is a
quintptr (an unsigned integer of the same size as a pointer).
More spiking.
New qml/gl package.
Merge branch 'gl-package' into painting-spike-gl
Fixed bridge spike to use new gl package.
Started handling slices. Fixed some doc links.
Merge branch 'master' into painting-spike-gl
Fix ragel command hints.
Merge branch 'master' into painting-spike-gl
Drop commented out hacks.
Trivial typing fixes in a couple of tests.
Explicitly select QT 5 when updating mocs.
Move metaObjectFor static function out of GoValue.
Take GoValue knowledge out of GoValueMetaObject.
Move implementation of GoValue::activate to meta.
Break GoValue and GoPaintedValue apart.
Added GoPaintedValueType and registration funcs.
Distinguish and use GoPaintedValue.
Fix bug introduced in type registration.