- performance improvements
  - removed 'identical' argument; this is now handled automatically
  - some minor API changes to SpotItem

Added (and disabled; doesn't work very well at the moment) code for using drawPixmapFragments in ScatterPlotItem

  - auto pan (center of view changes, but total range does not)
  - scale only to visible data (data outside of viewbox is ignored when auto-ranging)

SpinBox bugfix - improper handling of arguments to setOpts in integer mode

  - isocurveitem documentation
  - updates to GradientEditor and PlotItem docs
  - Fix for Canvas handling of item Z-position

  improved mouse/keyboard interaction
  bugfix in GLViewWidget.cameraPosition

Flowchart updates - added/fixed some display nodes
Merge from Kratz:
  - documentation updates
  - ComboBox class (updateList() allows entire item list to change while remembering previous setting)

Also cleaned up some context menu items