Anti Aliasing is broken

[bluesillybeard]

anti-aliasing is broken across the board

• text tool does not perform any anti-aliasing despite it being enabled.
• brush and eraser tools do not apply blending correctly and are only really usable with anti-aliasing disabled

Last tested on patch commit #04c5d4c6efca45661c0bbaeedb280ba93d3afc3c