Blender Git Loki

Another round of tweaks to new Preferences

- Removed doubled Cycles Compute Device text
- Moved header placement into menus panel
- Moved Text panel & rna to Interface
- Moved OpenGL Texture panel inside OpenGL panel
- Moved Color Picker Type to from System>Misc to Interface>Menus (eventually it'd be nice to include this option inside the color pickers themselves to make it more useful and discoverable)
- Combined all memory-related preferences (Undo + Console Scrollback + Sequencer Cache) in a Memory panel in System section (avoids needing previous Misc panel)
- Added correct greying out to Files > Auto Run Python Scripts panel
- Added flow layout to Save & Load checkboxes
- Rejiggered some of the Texture preferences to make more logical sense together
- A few other minor adjustments