* Added HDF5 exporter
* CSV exporter gets (x,y,y,y) export mode
* Updates to SVG, Matplotlib exporter
* Console can filter exceptions by string
* Added tick context menu to GradientEditorItem
* Added export feature to imageview
* Parameter trees:
- Option to save only user-editable values
- Option to set visible title of parameters separately from name
- Added experimental ParameterSystem for handling large systems of
interdependent parameters
- Auto-select editable portion of spinbox when editing
* Added Vector.__abs__
* Added replacement garbage collector for avoiding crashes on multithreaded Qt
* Fixed "illegal instruction" caused by closing file handle 7 on OSX
* configfile now reloads QtCore objects, Point, ColorMap, numpy arrays
* Avoid triggering recursion issues in exception handler
* Various bugfies and performance enhancements
- optional context menu for ImageItem
- inverted y-axis in Canvas (+y now points upward)
- extra __init__ arguments for Dock
- Transform can be constructed from Matrix4x4
- many others
