Proposal: make libplasmaquick semi-privare

[David Edmundson]

Can I request moving SVG and FrameSVG into PlasmaQuickPrivate

1) I need to tweak the API to get rid of the paint() methods and
instead add render hints to the pixmap() method

2) I want to destroy most of FrameSVG :)

3) I want to put in an implicit sharing of QSGTextures, exposed via
Plasma::SVG would make sense (I think) which makes them Quick related.