Blender Git Loki

Improve texture sampling. Don't revert the brush colour at end of
operation if the operation is used once for sampling palettes (though
the brush colour still changes during operator operation to display the
colour sampled). Also added area message describing use (possibly could
be used for value display too).

Palettes: Refining based on user feedback on blenderartists:

* Palette colors can be set to active brush by L-clicking
* Palette colors can be edited by ctrl-L-clicking (regular colours can
be edited by simply L-clicking)
* Palette colors can be deleted by hovering over them and pressing
delete or X

To make this work, an extra button property was added. Also I separated
the color button handling code since it was becoming too much of its
own.

Fix own buffer overflow when sampling colours, meant brush strength
could be overwritten.

User request: Add colours to palette when sampling with S and pressing
Left Click.

Also don't give a default palette to paint systems, it's not really
necessary and it can pollute the UI.

Merge trunk -r58364 into soc-2013-paint. Means new splash screen!

Use regular drag'n drop system for pasting colors. That was a fun patch
to write, it abuses the custom pointer of the drag system and required
patching the drag'n drop system to support freeing the pointer if
needed. The result is nice icons when dropping colours :). Unfortunately
the name of the operator is strangely not always visible when dragging
to a correct spot (such as the toolbar)

Fix linking of blenderplayer

Fix vertex painting not having palettes and colour sample operator (S)

Enable drag'n'drop of colours from any region to any other region.

Fix evil issue that prevented popping up a color widget if you had
closed a previous widget by clicking to a colour button next to it.

Also some style fixes and a better return value.

Allow copying of non gamma-corrected colors.

Fix memory leak in invalid drags, also add byte image case (should
probably be color corrected but I need a use case to test)

Uability feature to make palettes and other colour stuff work nice:
Support drag'n drop of colours from colour widgets.

This requires a few changes to the way colour pickers pop up, they now
spawn on mouse release instead of mouse press.

Dragging to another colour copies the first colour to the second.
Unfortunately there's no undo here yet.

* Palette colours get added to toolbar according to toolbar length.
* Add operator for adding colours.

Palette Colours are now visible.

Still no operator to add colours visible in UI but colours can be added
by using operator search (palette colour add)

Palettes only active on image painting currently

Merge trunk -r58316 into soc-2013-paint

Some renames, operators for adding colours to palette, fixes to
read/write of palettes, RNA properties of colours.

* Use writedata instead of writestruct.
* Vertex painting did not work due to own mistake in backbuffer
sampling.

File saving code for palettes.

Merge trunk -r58270 into soc-2013-paint