"warning": "Script returns errors"

Modified the wiki_url link to point to the MH site. To link to external sites may be frowned upon, but I don't want to maintain duplicate copies of the documentation. This is at any rate better than before, when the the link pointed to outdated info.

from perfection cat (sindra1961) 

Matrix().Scale --> Matrix.Scale

eg: XFCE file - /usr/share/xfce4/xkb/flags/tr.svg

Transformation for non-container objects was applied twice when they were USEd.
Get rid of confusing checks for special cases in USE.createGeom and use special
flag (instancing) which tells geometry is it "normal" geometry creation or
geometry creation initiated by USE node (SYMBOL would be handled differently
int this two cases)

Quick tests showed none regressions.

Suppose zero frictional part for case there's space or comma after
dot in float value. Inkscape sometimes uses such weird format.

- transform() only requires a single argument.
- support 'INVALID' as a unit suffix is present in some files created by docbook.

file from report [#26555] was raising an error becaues of this.
us.svg line 23
  <use xlink:href="#star" x=" 0.126"/>

Enable raytracing on OBJ materials always, not conforming to OBJ spec but this is annoying for newer software where raytracing is default.

the rig.

- Flipped the roll values on the default human metarig spine and neck.  This
  makes bending the rig forward have a positive rotation value, and bending
  back have a negative one.  More in line with user expectations.
- Improved get_pose_matrix_in_other_space() to account for bones with
  "inherit rotation" and/or "inherit scale" turned off.
- Added a text file giving credit to people who have contributed to Rigify
  financially or otherwise.

Moved operator registration for rig UI into the register function.  Not
really necessary, since the generated script doesn't act as an addon.  But
it keeps everything in one place.
Also added an unregister function for absolutely no reason.

Clean-up of the IK/FK snapping code.  Should be much more maintainable now.

Also changed rig id generation.  Rig id's now consist of a random
alphanumeric string 8 characters long, with the smallest 8 digits of seconds
since the epoc (in hex) at the time of rig generation appended on the end.
This results in a 16-character string that is ludicrously unlikely to
have any collisions between rigs.  36^8 * 16^8, with the 16^8 being very well
distributed over time.  Ah... paranoia.

- Added IK/FK snapping (both directions) for legs.
- Cleaned up another operator so that it works with undo.
- PEP8 cleanups. 

was missing undo push as Joshua pointed out.