* added few enum converters

* added precise MeasureString method

* added implicit operator from RectangleF to SvgViewBox

* SvgDocument can calculate its size in percentage
* SvgTransform collection can return all matrices multiplied

* added method to collect paths of children elements
* fixed possible bug getinheritedattribute

* fill can be null -> none in XML
* added type converters for enums
* added type converter for unitcollection
* fixes several viewbox bugs
* document can now draw into a given bitmap
* content of SVG tag is written (used by the text tag)
* changed font handling in text element, still need proper alignment
* changed intersparse character of SvgTransformConverter.cs to space, because inkscape couldn't parse comma
* added class diagram for basic shapes

SvgUnit comparison seems not to be working so added IsNone() method to correctly identify a none type.

Now handles values of none without throwing an exception. This bug could cause images to load very slowly.

Applies default values of 50% for radial gradient cx,cy and r. This prevents an OutOfMemory exception when loading svg files without these parameters specified.

No commit message