Changes in 1.18:
- Add support for dataset expressions when plotting
- Add axis-function widget for plotting axes which have a scale given by a function, or are linked to a different axis via a function
- Add stepped colour maps
- Support editing multiple datasets simultaneously in editor
- Add setting to fix aspect-ratio of graphs
- Add 'vcentre' line step mode for vertical step plots
- Add internal margin setting for grids to separate sub-plots
- Add pixel, pixel_wcs, fraction and linear_wcs FITS import coordinate system modes
- Add drop down toolbar button menu to create axis widgets
- More efficient widget dependency resolution
Bug fixes:
- Fix reversed 'broken'-axes
- Do not always draw axes above other widgets (fixes problem with key below axis)
- Fix use of transparency image when plotting non-square images
- Allow lists passed as xrange and yrange to create 2D dataset
- Fix FieldBool positioning for plugins
- QDP import: fix "no" values when used mixed with numbers
- Remove warning of log images with zeros
- For embedded mode, always return string for repr
- Workaround for windows appearing behind for Mac OS X