Based on patch [#28108] by Wintch Analyzer

[[Split portion of a mixed commit.]]

Reported by Tobias Kummer. Thanks! :) 

- added default options for unity3d, can add other defaults too

gives a few % speedup

from John Brown (jcbdigger) 
patch file:
    fbx_xna_unified-2011-08-02a_jcbdigger.patch


Option not to export Default Take

fbx_xna_unified-2011-08-01b_jcbdigger.patch

Only part of this patch has been applied (just the changes to the operator).

from John Brown (jcbdigger)

The patch has been modified, some of the changes I rather see applied as separate patches.

This commit adds/changes:
- Option to export XNA compatible armature rotations.
- Option not to export mesh edges.
- Always export armatures as 'Limb' type.
- dont write default cameras or camera switch when cameras are disabled.
- fix for (harmless) error where armature connections were written out twice.

also made some small style changes and commented unused function.

[[Split portion of a mixed commit.]]

patch [#27769] Small fixes for X3D exporter: not existing IndexedTriangleSet.creaseAngle, zero Viewpoint.orientation, ...

*Info from the tracker submission this patch resolves*

3. When exporting texture URL, new Blender 2.58 exporter writes URLs in the order: [basename, result of bpy_extras.io_utils.path_reference, absolute]. I propose to change this order to write the result of bpy_extras.io_utils.path_reference *first*. Reasons:
-- Result of bpy_extras.io_utils.path_reference is controlled by user (through path_mode). By setting it correctly, user can make sure that 1st url matches (which is nice for 3d viewer, also avoids warnings from view3dcene that one url along the way was not available).
-- This also makes the results of 2.58 exporter more similar to how 2.57 behaved. In 2.57, the relative path "os.path.relpath(filepath_full, relpath)" was first, then basename, then absolute name. And that was good, in my opinion, as relative path has the best chance of success and is more directly controlled by user. (New "bpy_extras.io_utils.path_reference" is even better, so kudos for implementing it.)

4. Finally, a trivial fix to the formatting of output "<TextureTransform..." in X3D. Without this fix, "<TextureTransform" and "translation=" are on the same output line, separated by a lot of whitespaces (taken from ident_step).

*Some code improvements like if -> elif

bug #2, zero length axis.

Tested using the file 'FBX_Export_Glitched.blend' from report: [#27964]

        also clear temp meshes after export.