Vispy

- Fix discrete colormap ordering (1668)
- Fix various examples (1671, 1676)
- Fix Jupyter extension zoom direction (1679)

- Update PyQt5/PySide2 to use newer GL API
- Update to PyQt5 as default backend
- New Cython-based text rendering option
- New WindbarbVisual
- Improved JupyterLab/Notebook widget (experimental)
- Fix various memory leaks
- Various optimizations and bug fixes

- Workaround added to fix ImportError with matplotlib 2.2+ (1437)

- Fix PyPI packaging to include LICENSE.txt
- Fix initial axis limits in PlotWidget (1386)
- Fix zoom event position in Pyglet backend (1388)
- Fix camera importing (1389, 1172)
- Refactor `EllipseVisual` and `RectangleVisual` (1387, 1349)
- Fix `one_scene_four_cams.py` example (1391, 1124)
- Add `two_qt_widgets.py` example (1392, 1298)
- Fix order of alignment values for proper processing (1395, 641)

- Fix 'doc' directory being installed with source tarball
- Fix 'ArrowVisual' when used with a Scene camera and in 3D space
- Fix 'SphereVisual' rows/cols order in 'latitude' method
- Fix DPI calculation on linux when xrandr returns 0mm screen dimension

- Major refactor of all cameras and visuals
- Add support for wxPython 4.0+ (project phoenix)
- Improve Jupyter Notebook support (not full support)
- Improve Python 3 support
- Add colormaps
- Add various new visuals `GridMesh`, `BoxVisual`, `PlaneVisual`, etc.
- Various bug fixes and performance improvements (177+ pull requests)
- Remove experimental matplotlib backend (`mpl_plot`)
- Drop Python 2.6 support