.Net 3.5 Support and Rendering Improvements (Markers, TSpans, Paths, etc.)

In order to get this library working properly on a project of mine, I have been making a number of tweaks / improvements to the SVG rendering engine.  I thought it would be useful if these changes were included in the official project.  If you need help with merging these or have any questions about the exact changes made, let me know.