Cycles: Fix Caustic tooltips.

Now that the option has been reversed, the tooltips should be changed too.
Thanks to David Black, for bringing this up!
Cycles: Several fixes for Presets.

* Fix caustic properties, was not updated.
* Remove wrong items, leftovers from panel splitting.
* Add missing items. Even if the bundled presets do not set those, a user expects that all properties inside the panel are taken into account, when adding a new preset.
No need for try/except in D766
Fix T41419: Quick Smoke doesn´t work with Cycles

Now the Quick Smoke operator creates a basic node setup for smoke and fire. This could be made more fancy still, but that's for later. :)
Fix T41740: Different behaviour of custom hotkey

Quick fix, this is actually a demonstration of why we should use modal keymaps!
We can give any event to *start* the op, but then hard-code how to *end* it... tsk.
Fix for line style shader nodes also shown in the Add menu of other shader types.

Problem report by Nahuel Belich through Facebook, thanks!
Some updates for Quick Smoke / Cycles.

* Add Density multiplier.
* Use Smoke color attribute.

Patch by Gottfried Hofmann, with some small tweaks by myself.
Differential revision: https://developer.blender.org/D776
Fix T41737 using append from menu will result in error message

message in terminal was: RNA_boolean_get: WM_OT_append.relative_path not found.
Added check for existence of the relative path property which was removed from append
since it is not needed and used.
Update readme for Blender 2.72.
Several tweaks for Quick Smoke:

* Improved Cycles fire, patch by Gottfried Hofmann. Differential revision: https://developer.blender.org/D777

* Added Smoke + Fire type to the operator too.

* Cleanup.
Cycles / OSL: Add a conductive fresnel shader template.

This adds a fresnel conductive OSL preset to the Text Editor. Based on a patch by Lukas Stockner.
Differential revision: https://developer.blender.org/D145

See the differential for details.
Comment out SVM fresnel_conductor() function for now, still unused.
Fix building as Python module (manpage-generation)
Fix T41746: WPaint: gradient+mirror fails
Attempt to fix compilation error on ubuntu linux
Fix T41703: Blender crashes trying to load character file.

Core of the issue is that pointcache handling in depsgraph were (re-) tagging
for update some objects on hidden layers, when all their dependencies remained
untag.

Since we do not want to update objects on hidden layers, take this data into account
when flushing pointcache.

Investigations and org patch by self, reviews, advices and final patch by sergey, many thanks! :)
Fix T41573: Compositing reroute converts floats to red color

At compo level, only skip data type conversion if both ends of a link do not require it.

Thanks to Lukas for advices and review.
Fix T41744: Hidden keymap properties uneditable

For UI & operator toolbar this makes sense,
but for keymaps - hidden props can make an important difference.
Fix crash happening with external engines and dependent objects in an invisible layers
CMake: Add missing WITH_OPENIMAGEIO define