Merge commit '43c59b1d943958737d0f1d5b303d0b4125094b82'
Added Render Output Method "XML File" as in old Blender 2.49 exporter. Default is to export to tmp directory, but can be changed in Render -> "Output Settings" Panel.
Fixed relative Paths for XML output.
Render Animation: reorganisation of file saving from YafaRay`s ImageHandler. Now only supported file formats are selectable, also for Render Method "Image File" the images will be saved in its own folder (yaf_ani) with frame number as filenames. Default Image output file format is EXR now, supports alpha and depth mask in file saving by default if enabled. Sadly i can not disable file saving from Blenders Animation rendering due to the Python API restriction. Also some code clean up in exporter files. Here is a screenshot of the changes for explanation: http://dl.dropbox.com/u/21229169/Render_Output.jpg
changed absorption distance precision to 5
changed absorption distance precision to 5 (reverse-merged from commit 6bf14381ae4f6bd05b0be093c839a99747d03d42)
added digit points to absorption distance and dispersion power (now 4 digits)
Exporter always uses the the angle from option "Auto Smooth" whether it is enabled  in object data, normals panel or not...
Changed it so it only use this parameter if "AutoSmooth" enabled, else it uses shade smooth for the mesh with a value of 181 degr (as it was in old 2.49 exporter). (cherry-picking from commit df0086b6170432c6ac8e4420cff9812632d0edce)
temp fix for textures with transparency and use alpha, image with alpha channel and color info should render again. Materials and texture mapping need some more testing.
Some fixes in converter and some ui cleaning in world buttons.
temp fix for textures with transparency and use alpha, image with alpha channel and color info should render again, but needs materials and texture mapping need some more testing.
Some fixes in converter and some ui cleaning in world buttons.
Material UI redesign based on proposals from samo, also implemented ior presets. Some pep8 cleaning.

Here are the proposals and the implementation in 2.57 exporter:
http://dl.dropbox.com/u/21229169/UI%20Redesign%20Materials%20in%20257.jpg
Marble procedural and IES File loading fix, IOR Preset menu code cleaning
Mirror color texture mapping for glass material fixed:
http://dl.dropbox.com/u/21229169/Col_Mir_mapping_for_glass.jpg
Added back Image sampling panel, with "Use Alpha", "Calculate Alpha", "Fplip X/Y Axis",
Interpolation and Exposure adjust for Images also. Here are some Interpolation Examples:
http://dl.dropbox.com/u/21229169/none.png
http://dl.dropbox.com/u/21229169/bicubic.png
http://dl.dropbox.com/u/21229169/bilinear.png
Enable compositing presets in camera display panel, could be nice for camera / scene setup
in yafaray also. Works only in Blender 2.57 rev. >= 36590.

Example: http://www.pasteall.org/pic/show.php?id=12124
Dupligroup fix for empty object type, see report: http://www.yafaray.org/node/461

Test File should work now: http://www.yafaray.org/sites/default/files/issues/dupli_group.blend

One issue remains though: external linking of dupli groups work, but not materials....
Changed camera transformation matrix from local to world, so now it gives correct render results if camera is parented or constrained.

Test File: http://www.yafaray.org/phpBB3/download/file.php?id=4426
Examples: http://www.yafaray.org/phpBB3/download/file.php?id=4737&amp;t=1
Python raises errors if object has no material assigned (e.g. refresh preview in materials), added some checks there.
Add font (text) support, see post on forum:
http://www.yafaray.org/community/forum/viewtopic.php?p=24316#p24316
Thank you Atom for the report and fix, also smooth angel for text objects 60 degr
gives nicer results.
Test File:  http://dl.dropbox.com/u/21229169/test_font.blend
Fix of own introduced bug in saving image files for animation, can not set file format, file
output path and exr zbuff in render context. TODO: disable image writing to disk from blender, currently not possible with 2.57 python API.
added missing particle panels, also enabled and moved strand settings to particle settings, some code cleaning too...
removed some prints, also fix for recent panel name change in blender (rev. 37269)