temporary fix for text parameter ignoring expanded option
Don't use os.EX_OK in pg.exit()

  - Support for dynamic downsampling and view clipping in PlotDataItem / PlotItem
  - fixed __truediv__ handling
  - ViewBox updates to fix aspect locking (still broken)
  - AxisItem tries to be more clever about when to display tick text
  - Fix segmentation fault caused by exception inside GraphicsItem.paint()
  - Added 'x' scatter plot symbol
  - pg.mkPen supports dashes

This fixes memory leaks with PyQt 4.10 _except_ when using makeQImage(copy=False).
Tested on 4.9.3 and 4.10.2; need to be tested against other versions.

Minor edits

- fixed auto-levelling when normalization options change
- added autoHistogramRange argument to setImage

Configure matplotlib to use PySide in MatplotlibWidget

Fixed bugs in functions weave usage
Documented ROI signals
Fixed 3D view updating after every scene change

imageview fix

AxisItem correctly handles scaling with values that are not power of 10
Can remove items from legend
updated plotItem setLogMode to allow unspecified axes

PolyLineROI.getArrayRegion correctly applies mask to N-dimensional data
fixed multiprocess for python2.6 compatibility

Added antialiasing to GL line items