make custom palette available for diverging color scheme

[rysebaert]

[mthh]

Thanks for the report !
I'm not totally sure to solve this issue as proposed (i.e. add the "custom palette" option also for "diverging scheme").

In fact, it is already possible to create a custom diverging scheme with the proposed option (even if it is in the "sequential scheme"). The problem is rather that the "custom palette" option is not in the right place in my opinion.

I think we should not have "sequential scheme" (including custom palette possibility) OR "diverging scheme" (including custom palette possibility) but rather "sequential scheme" OR "diverging scheme" OR "custom palette" (3 radios buttons instead of two - and we remove the small "Custom palette ?" text that is in italic).

What do you think ?

[mthh]

I postpone the correction of this issue to version 0.9.0.
I think I should take the opportunity of this enhancement to improve the appearance of some of the elements in this panel.

[rysebaert]

Totally agree with the solution you propose !

[mthh]

Awesome !
I will release 0.8.15 tomorrow (if nothing bad happens during some last tests!) then I will start working on this discretisation panel.