Fix T42233: Python property ignores 'PROPORTIONAL'
Cleanup: spelling (D831)
CMake: Attempted to copy manual for py-module
Fix use-after free (own error)
Add missing `CustomData_duplicate_referenced_layer_n` and deduplicate code.

CustomData_duplicate_referenced_layer_n not used in master currently, but need it
in mesh tranfer branch.
Cleanup for previous own commit (sorry...)
Cycles: Be ready for new OIIO and OSL libraries

Even tho it's not 100% clear when we'll switch to OSL-1.6 we'd better
start preparing earlier for this, so we don't spend time on this later.

Plus this code helps troubleshooting some OSL issues, which requires
testing with latest versions of OSL.
Cycles: Remove compatibility code for OSL-1.4

That code was mainly needed for the transition period, now we've
got all platforms updated to new OSL.

Plus there are some crucial fixes baking in the current upstream
sources which we'll need to have for the next Blender release.
Code cleanup: Replace magic constants with defines

From quich search didn't see where the flags are used apart from
RNA currently, but i might have missed something.
Add utility macros to clamp all elements of 2,3,4 component vectors
Fix T42445: Clamp flag has no effect on result value in Math and MixRGB shader nodes (Blender Render)

Quite striaghtforward implementation, with the only weird thing that for some reason
my video driver wasn't happy with calling the function "clamp" giving some weirdo
shader compilation error messages.

Called the GPU function clamp_val which can handle float and vec3.
Fix-for-fix ik-spline clamp existing files too
Fix T42289: 'Make single user' not registered in history
Fix T42408: FSAA affects Cycles Image Compositing

Use FSAA settings only if current render engine is BI or GE/

That's for until we'll support FSAA in Cycles or other render engines.
BMesh dissolve: enable use_verts for edge dissolve (by default)
Fix T42411: Camera inside volume + particle dupli (object/group) doesn't work

The issue was caused by missing current object instance initialization after
object was ignored for instance push.
Cycles: Don't check shader for volume when checking if camera is inside volume

Intersection code already ignores objects without volume closure so checking it
afterwards is not needed.
Code cleanup: Replace magic number with verbose name for math node operations

Should be no functional changes, just much less cryptic code.
Simplify node frame detach operators, based on T34670 by @julien.

* The `NODE_OT_parent_clear` operator has been removed. This was a very
simplistic operator that detached every selected node, which is not very
useful in case of hierarchical frames. The `NODE_OT_detach` operator
only detaches the top parent nodes in the selection, keeping the
hierarchy of selected nodes intact.

* The `ALT+P` shortcut has been reassigned to the `NODE_OT_detach`
operator which replaces the previous `NODE_OT_clear` mapping with
similar behavior (also gives a menu entry shortcut now).

* Shortcuts for `NODE_OT_detach_translate_attach` have been removed, due
to crowded and messy keymap and unintuitive shortcut `ALT+F`. This macro
operator is still registered, in case hardcore users want to make their
own keymaps, but not mapped by default. Node keymaps may need some
redesign in the future for these things.
Debug: print output on --debug-fpe

in practice often we want to breakpoint here (instead of flooding output)
but its confusing the option does nothing in release builds.

Devs can comment out locally.