* Fix context.cloth, was not being set correct.
* Fix errors with context pinning, scripts should
not assume context.object to be there.
* Always show preview even if e.g. the material is not
set, to keep ID buttons from jumping while you're
using them.
* Added more material buttons by William. Thanks.
I made some minor adjustments and added Specular Shader Model RNA.
* Code cleanup and some consistency tweaks of button files.
Notes: Preview render now only shows up when there is an active world, material, texture or lamp.
* Made sure initial panels with ID Datablocks are shown, even when no block is active.
Added a new template for layer-buttons, which auto-determines the layout of the buttons instead of relying on some hardcoded pattern for n-layers (i.e. 16 or 20 currently). This is a still bit rough, and could do with some refining to allow us to define what extra info (icons) should get drawn on the buttons or so.
Currently, this is only used in the Armature buttons to allow showing/hiding layers.
* Context now allows pinning a datablock, independent of
selection.
* Initial ID browse buttons for most buttons tabs.
* Browsing from world to texture now displays world textures
again, but is a bit of a hack, not sure there is a right
way to do this.
* There's a button to switch between active materials and
textures now, only temporary though.
* There's some code to put context part in own region,
disabled still because it doesn't work that well yet.
* Added new modifier tab.
* Fixed problems when no object was selected after delete.
* Added initial Armature, Bone, Curve and Font panels, by William Reynish (Billrey). Thanks!
* Small RNA changes
* Commit revision 20240 and 20268 from trunk. ("Mouse wheel zoom lost after rendering.")
