Gmoccapy: Fix odd spindle behavior when using G96

[Sigma1912]

Fixes issue #3447:

• gui spindle speed display showing a very large number when G96 (CSS) mode is used
• spindle.0.speed-out pin being reset to a wrong value when the gui spindle buttons are updated after calling G96 through MDI

[andypugh]

Can you rebase this on 2.9? It's a clear bug.

[Sigma1912]

I notice that the relevant functions have been somewhat changed in master and I assume that the added lines will also need to be put into my two new functions.
This is 2.9:

And this is what it should look like in master (the three last lines in each function are new additions made by @hansu ):

I'm not sure how this should be handled. Please advice.

[hansu]

27e76fd fixes a minor bug so I added it only in master. But can go into 2.9 as well.
Should I cherry pick that into 2.9? Then you have the same base for the lines you are changing/fixing.

[Sigma1912]

So can you put this commit into 2.9 before I create mine or should I try to cherry pick this into my PR?

[hansu]

No the above mentioned commit is already in 2.9, included in the 2.9.4 release. Github confused me a bit.

[Sigma1912]

I see, so it seems that my repo is not up to date, thanks.

[Sigma1912]

See rebased and improved PR #3454