- Added support for the "gradientTransform" attribute on both linear and
  radial gradients. The matrix in this attribute needs to be applied to
  attributes with coordinate values on the gradient element in order to
  transform them into the correct coordinate space.

- Added support for a value of "pad" for the "spreadMode" attribute on
  both linear and radial gradients. This is the default value but was not
  implemented correctly. In order to implement, we examine the properties
  of the gradient along with the element to which the gradient is being
  applied to determine if we need to expand the bounds of the gradient to
  fill the element. If so, we do so and adjust the color stops and
  positions so they are correct for the new gradient bounds.

- Divided ISvgStylable into ISvgBoundable and ISvgStylable. The
  SvgUnit.ToDeviceValue method just needs bounds so it can take
  ISvgBoundable. Moved SvgDocument.GetDimensions() to SvgFragment and made
  SvgFragment ISvgBoundable.

- Fixed a bug in SvgFragment.PushTransforms where it was calling the
  SvgUnit.ToDeviceValue overload that takes no parameters. This overload
  doesn't work if the value being converted is a percentage. (The overload
  should probably be removed entirely, but we didn't take that on in this
  commit.)

- Fixed an issue in SvgGroup.Bounds where a child with empty bounds would
  cause the group's bounds to be reported as empty.

- Fixed broken build by adding missing SvgMarker.MarkerUnits property.

- Converted files that we touched with mixed tabs and spaces to spaces.
  Also removed unused usings from files we touched.

- Converted SvgLinearGradientServer to use properties without backing
  fields for X1, Y1, etc. in order to match SvgRadialGradientServer.

- Moved default value assignments into constructors for consistency.

Moved Display="none" hack & Added .Render check for : if (!Visible ||
!Displayable)

Also, minor change to logic of SvgBoolConverter so bad visibility values
(other than "hidden" or "collapse") wouldn't accidentally hide element

To get the Bounds, the Union method of the rectangle must be called only when the first rectangle has been set. If the Renctangle is empty, use the first children's Bound, as a rectangle.

https://github.com/vvvv/SVG/issues/23#issuecomment-25747963

Support "none" in Fill value if inherited from parent

- Changes to get texts displaying bold / normal weight
- Changes to get textspans work correctly
- Made (semi-hardcoded) document metadata section - allow reading and regurgitating metdata tag from an original source document
- Included image
- Modified paths to allow for scientific notation
- Included ability to have markers for path ends (arrow ends etc)

* fixed missing files

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

- Refactored SvgElementFactory to use the new SvgElementAttribute to get available elements.

- Fixed #6324: SvgElement.PushTransforms and ViewBox - not necessarily related to ViewBox but every   element was 'resetting' the current graphics transform if the element contained it's own transform. This 
  was a very small fix for a large problem (SvgElement.PushTransforms Matrix transformMatrix = new   Matrix(); changed to Matrix transformMatrix = renderer.Transform; in order to inherit the current   transform.)
- Fixed #6344: Parsing document incorrectly parents elements when it encounters empty nodes which are   in a different namespace. Empty nodes are now ignored and current nodes are closed as required. We'll 
  see how this fix goes.
- Fixed #6381: Units in inches are incorrectly parsed as millimeters - problem was caused by some   copy/paste work.
- Graphics has been replaced by SvgRenderer. This is essentially a wrapper around graphics but will allow
  custom svg related properties in the future when needed.
- Removed ISvgRenderer: A concrete implementation is suitable.
- SvgElement.ElementName has been changed to non-virtual and is set by the parser instead of the   developer having to specify it when developing the class.
- Added more XML API documentation.