Added support for modifying a wxD2DPathData after being flushed
Implemented wxD2DPathData::Transform
Fixed wxD2DPathData::GetCurrentPoint and added transformation support
Fixed a problem with wxD2DPathData::AddArc implementation where some arcs would have a wrong center point and arc length
Added wxD2DPathData::AddCircle and wxD2DPathData::AddEllipse methods
Cleaned up wxD2DPathData::AddArc implementation
Added check to wxD2DPathData::CloseSubpath method to ensure there is a currently open path