when QT_DEVICE_PIXELRATIO is something different from 1,
the pixmaps generated by Svg will be scaled up to give a proper texture.
This is complementary but not replacing our current approach:
the pixelratio that can be accessed by units is now in relation to the qt pixel ratio,
spacings are also adjusted accordingly (therefore, spaces and sizes won't
need an integer value like pixelratio)
svg introduces also a scaleFactor property (that is pretty much like its old pixelRatio)
basically, scalefactor, will scale both the textures and all the reported sizes,
(old method) pixelratio just scales textures without altering measures
(like qt pixelratio likes)
Change-Id: I304aa0d80abf76abafac239be185dd3b2ab741b7
REVIEW:122673
148e0022f6