Merge branch 'develop'

This is 0.9.2! See the CHANGELOG.

Merge branch 'develop'

Welcome to 0.9.1!

Merge branch 'package_reorganization' into develop

ACQ4 now uses a more standard python package layout.
* /lib is renamed to /acq4  (and all imports updated accordingly)
* pyqtgraph now lives in /acq4/pyqtgraph and is directly importable
  by using pyqtgraph-core subtree
* Added distutils and debian packaging infrastructure
* /documentation is now /doc

Merge tag 'pyqtgraph-0.9.8' into pyqtgraph-core

Merge tag 'pyqtgraph-0.9.7' into pyqtgraph-core

Merge branch 'release-0.9.8'

Bugfixes:

  - ArrowItem auto range now works correctly
  - Dock drag/drop fixed on PySide
  - Made padding behavior consistent across ViewBox methods
  - Fixed MeshData / python2.6 incompatibility
  - Fixed ScatterPlotItem.setSize and .setPointData
  - Workaround for PySide bug; GradientEditor fixed
  - Prefer initially selecting PlotItem rather then ViewBox when exporting
  - Fixed python3 import error with flowcharts

Cleaned up examples, made code editable from example loader
Minor documentation updates

Features:

  - Added GraphItem class for displaying networks/trees
  - Added ColorMap class for mapping linear gradients and generating lookup tables
    (Provides gradient editor functionality without the GUI)
  - Added ColorMapWidget for complex user-defined color mapping
  - Added ScatterPlotWidget for exploring relationships in multi-column tables
  - Added ErrorBarItem
  - SVG and image exporters can now copy to clipboard
  - PlotItem gets new methods: addLine, setLabels, and listDataItems
  - AxisItem gets setTickFont method
  - Added functions.arrayToQPath, shared between GraphItem and PlotCurveItem
  - Added gradient editors to parametertree
  - Expanded documentation, added beginning of Qt crash course

Bugfixes:
  - Fixed auto-ranging bugs: ViewBox now properly handles pixel-padding around data items
  - ViewBox ignores bounds of zoom-rect when auto ranging
  - Fixed AxisItem artifacts
  - Fixed GraphicsItem.pixelVector caching bugs and simplified workaround for fp-precision errors
  - LinearRegionItem.hoverEvent obeys 'movable' flag                                                                                                                                         
  - Fixed PlotDataItem nan masking bugs                                                                                                                                                      
  - Workaround for segmentation fault in QPainter.drawPixmapFragments                                                                                                                        
  - multiprocess and RemoteGraphicsView work correctly in Windows.                                                                                                                           
  - Expanded python 3 support                                                                                                                                                                
  - Silenced weave errors by default                                                                                                                                                         
  - Fixed " 'win' in sys.platform " occurrences matching 'darwin' (duh)
  - Workaround for change in QImage API (PyQt 4.9.6)
  - Fixed axis ordering bug in GLScatterPlotItem

Plotting performance improvements:

  - AxisItem shows fewer tick levels in some cases.
  - Lots of boundingRect and dataBounds caching
    (improves ViewBox auto-range performance, especially with multiple plots)
  - GraphicsScene avoids testing for hover intersections with non-hoverable items
    (much less slowdown when moving mouse over plots)

Improved performance for remote plotting:
  - reduced cost of transferring arrays between processes (pickle is too slow)
  - avoid unnecessary synchronous calls

Added RemoteSpeedTest example

Documentation:

- Added documentation on export system
- Added flowchart documentation and custom node example

Bugfixes: 
- prevent PlotCurveItem drawing shadow when unnecessary
- deprecated flowchart.Node.__getattr__ -- causes too many problems.