Assumed patient orientation is black on black for 3D skin dose map views

[Ed McDonagh]

For 2D views, the text is black on white. For 3D views, the colours switch, but the assumed view (ie the HFS bit) doesn't, and hence appears to disappear!

Assigned to @dplatten on the assumption he can find it quickest!

[David Platten]

I'll fix that.

[David Platten]

Made patient orientation toggle from black to white text when user toggles between 2D and 3D skin dose map view. Fixes issue #519

→ <<cset b1ee5e738675>>