- Fix issues with calculating the next coordinate after a close figure
and a relative move
- Allow the std. deviation in a gaussian blur to be a float.
- Allow "none" for a unit collection
- Allow a marker to scale with either the stroke width or the use a
custom coordinate space
- Allow gradients to reference other gradients defined later in the SVG
- Respect the font and fill styles of TextSpan elements.  Current
support is still partial.
- Fix href attribute bug on the SVG use element

- Implemented .Net 3.5 support mostly by removing ISvgEventCaller
functionality in .Net 3.5 build
- Added ability to parse orient="auto"
- Added ability to parse colors such as rgb(#%, #%, #%)
- Fixed marker rendering implementation

* added few enum converters