Bug fixes: Gradients and Filters

- Support of generic fonts (serif, sans-serif, monospace)
- Initial support of filters
- Fixes to gradient rendering
Text on a Path & SVG Fonts

- Extraction interface for SvgRenderer
- Initial support for Text on a Path
- Initial support for Svg Fonts
- Support for symbol element
- Minor bug fixes with image pattern rendering
- Additional support for Text whitespace modes
Bug Fixes

- Fixing path parsing algorithm to deal with nuanced arc cases and
hopefully improve performance
- Attempts at better memory management
- Working toward getting symbols to render correctly
Merge remote-tracking branch 'upstream/master'
Gradient, Pattern, and Clip Fixes

- Better parser for dealing with parsing edge cases
- Fix corner radius for rectangles
- Fix to gradients.  Most tests now pass
- Add the possibility for a fallback paint server
- Initial fixes to clipping
- Start marking passed test
- Fixes to pattern rendering
Bug Fixes

- Improving rendering of SVG images
- Allow markers on lines, polygons, and polylines
- Implement different line joins and line caps
- Improve CSS handling
External CSS Option for SVGDocument

Added External Cascading Style Sheet Option to SVGDocument.
Merge pull request #93 from erdomke/master

Initial Filter, Svg Font, and Text on a Path Support
Merge pull request #98 from sschurig/master

External CSS Option for SVGDocument
merged
Fixed up empty string fix