Fix for sprite rendering. Merge alpha and opaque plotting functions svn path=/import/netsurf/; revision=1240
Standardise swis.h include svn path=/import/netsurf/; revision=1238
Rationalise image redraw. Supply background colour when redrawing contents Reenable printing of background images Require Tinct 0.07 svn path=/import/netsurf/; revision=1234