- isocurves
 - array processing through gradientwidget

 (this *should* be a backward-compatible change)

  - curves enable antialiasing when exporting to image
  - plotitems hide button during export

  GraphicsObject - corrected bug in viewPos() method
  WidgetGroup - allow bound methods in interfaces
  parametertree - fixed crash when calling remove from context menu

 - initialization error in plotcurveitem
 - performance fix for plotdataitem

Made APIs more complete and consistent.

  - Corrected ImageItem.setRect transformation order  
  - PlotCurveItem uses nkPen for interpreting shadowPen arguments
  - PlotItem and PlotWidget wrap a few more missing methods from ViewBox

documentation update
removed documentation builds from repo.

Fixed a few bugs in AxisItem

Moved GraphicsScene to its own directory, added exportDialog
Removed old export options from PlotItem / ViewBox (will re-enable once they are working again)

 - volumetric rendering
 - isosurfaces, mesh rendering
 - basic transformation and parent/child functionality

 - rotate/scalable view widget
 - volumetric data item

 - disabled opengl (performance issues in Qt 4.7)
 - numerous caching changes (disabled deviceCoordinateCache due to performance issues)
 - speed up loading large images in ImageView
 - bugfixes from Ingo Breßler
 - Transform rotation bugfix
 - Added debug module
 - Major performance enhancements for scatterplot, fixed point clicking issues
     ** API change for scatterplot click signals
 - Drawing on ImageItem is working well now
 - PlotItem downsampling no longer uses scipy.signal.resample (this was creating artifacts)
 - Fixed ViewBox behavior when aspect-locked

 - numerous fixes in close() functions
 - added Transform class
 - ROI widgets now operate in degrees instead of radians for easier Qt compatibility