Made some tweaks to transformation matrix of <svg> node to make
it so origin from Inkscape matches Blender origin.

Currently only affects files from Inkscape, for others it's not
so much clear what origin should be.

Based on the patch from aldero (juanC), thanks!

make addons blender versions consistent

Apparently internally SVG importer was using 90 points per blender unit,
not per inch. This made files importing with unexpectable dimensions
which could be really harmful if you're importing blueprints as references.

Now SVG importer is using 90 points per inch, which makes imported files
has correct dimensions in both Metric and Imperal unit systems.

However, there's one possible downside -- imported files would look
smaller in blender units system.

finished

Additional changes:

- Fixed wrong pop of rectangle area (function wasn't called)
- Removed unused code

Adding UNDO flag to import operators. Made this only for trunk addons.

- remove/comment unused variables
- remove unused imports
- fixed some bugs using incorrect variables

Update current point position when closing path is needed.

Added missed copyright entry in add-on info block -- svg-arc to
blender beziers calculation was made by JM Soler.

JM, sorry for this :)

handle exceptions for reading non XML files - cant decode or parse, real errors in code will still raise exceptions.

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"/>

- Handle situation when last point of path segment has got the same position,
  as first segment point. It used by Illustrator to set up handles of first
  point and to make segment closed.
  Not sure about standatr about this, maybe SVG files from other editors should
  be handled in different way, if it'll be issues -- could be easily fixed.
- Use black fill as default (all viewers/editors use this).

- Fixed rotation matrix
- Fixed unneeded deformation caused by interior transformation for
  used objects (different tags should be handled differently),
  also, SYMBOL tag could have viewBox
- Implemented parsing of colors in rgb(r,g,b) notation

- Fixed exception caused by spaces after last semicolon in style
- Ignore svg namespage in tag names when detecting geometry class

- Remove unneeded "global" specificaitons
- Fixed parsing for paths which contains floating-point numbers
  in format like 10e-2
- Fixes aspect ration when viewBox is specified

 - Rect
 - Circle
 - Ellipse
 - Line
 - Polyline
 - Polygon

 Also fixed incorrect constant for cm/mm scaling

- Fixed silly error caused by copy-pasteing code from class
  (accessing to self from simple function)
- Fix for illustrator path format -- it doesn't place spaces before
  "minus" sign of next number. Maybe it's time to go out from stypid
  string replacement-splitting to slower but smarter token parser?

- Fixed incorrect usage of 255 color range -- each component should
  be from segment [0..1]
- Added "style" tag parsing