Use QPainter::CompositionMode for all internal blending variables and functions
Fix labels not updating for atlas prints when blend mode is applied
small update of the UI of the symbollayers widgets
Merge pull request #512 from nyalldawson/blend_mode_fixes

Some blending fixes and code cleanup
GML parser boundedBy fix
[sextante] moved SilentProgress to independent module
[sextante] more tests
Merge pull request #513 from olivierdalang/SymbolLayerWidgetsUISmallUpdate

small update of the UI of the symbollayers widgets