Proportional edit:
- Proportional mode added to header as button/menu. Including new option
to have only connected geometry influenced.
- Added icons for proportional & proportional modes
- Make proportional edit data part of Scene, so all gets saved.
The Global flag G_PROPORTIONAL was removed
- Made sure #defines get used properly, also tweaked order for proportional
so it starts with regular 'smooth' by default.
- Use ALT+O in editmode to switch to new proportional 'connected' mode
Other UI stuff:
- in EditMode, the layer buttons get hidden... the amount of icons in
3d header grows to fast. :)
- made less ugly icons for the Manipulators. Still can be better.
- Added alpha-filter for pre-processing Icon-image, giving nicer display
of icon-antialising on dark or bright backdrops
- disabled Manipulators when in editmode, and current layers don't show
the edited data.
- Added the value used to define Normal size (editmode draw) in Scene too,
so it gets saved.