This adds the fontset support into save_xml
- Adds fontset_name into the text attributes
- Adds the fontset definitions
- glue to read fontsets from map
2. PostGIS plug-in - optional 'multiple_geometries' parameter to control how Multi* geometries built.
3. MarkersSymbolizer (work in progress) to render vector shapes (markers) alonh a path with collision detection.
- libxml2 support
- strict error handling while parsing XML map files
- implemented save_map()
- removed some duplicate defaults
- all symbolizers with icons share a common base class now