math/wxmaxima: Update to 20.04.0
- Resolved a crash on right-clicking a GroupCell.
- View/Invert worksheet brightness now toggles an instant dark worksheet mode.
- Removed an unnecessary info dialogue on startup.
- Right-click-suggestions for similar command names.
- Corrected the initial slideshow size.
- A more stable language selection mechanism.
- An Ukrainian translation update.
- A Russian translation update.
- Add a German manual page.
- Help works again in the German translation.
- Extended the "fitting data" example.
- An example on how to iterate through lists efficiently.
- Many spelling corrections and better formulations.
- A big number of small bug-fixes
- A noticeable speed up.
Approved by: gerald (mentor)
Differential Revision: https://reviews.freebsd.org/D24573