Updated to newest octoWS2811 lib (for teensy 4.0) + include a "Test Mode" over Serial

[fat-fred]

Adapted the code for the newest octoWS2811 and include a new extented version of the lib (to support also Teensy 4.0)

• only Teensy 4.0 is testet by me, 3.1/3.2 not (but compiles)

Also include a new Variable to Test the serial connection. (Had in the beginning some Problems, but was DOF Problem)

[MikePinball]

I have some initial comments on this update:

1. It seems like it hasn't been tested on Teensy 3.2. I will do that but it will take a few days.
2. In the 1.03 code, I stripped out all of the conditional CPU #defines because they weren't needed and I wanted the code to be easier to read. I'm still not sure they all need to be added back because the Teensy 4.0 source code is in a different source file in any case. It is unusual that Paul decided to keep the same .H file, but then created a separate CPP file. Perhaps he decided that there were too many changes which made the code harder to read (which is the same rationale for me taking out the other #defines).
3. The code in "OctoWS2811Ext::busy" seems wrong. I hard-coded 50us because I couldn't find anything that changed the timeout based on WS2813 LEDs. As far as I know we don't use WS2813 LEDs in Pincabs so I went with the documented timeout of 50us.
4. We should update the version number in the INO file to 1.04.

[fat-fred]

1. O.K.

2.1 I dont know what we here really need. So I CANT do this.
2.2 I think it should be better to let it nearly original. The last days there are more updates for the lib. so it should be easer to update.

3. done

4. done

[MikePinball]

Agreed on item 2. Maintenance will be easier if we keep in sync with Paul's code. I may give the feedback back to him directly on the PJRC forum.

Thank for the fixes to items 3 and 4.

Let's do some more testing before committing this code.

[lizardking]

I'm happy to hear that there is new stuff developed for this old project. I'll be happy to integrate the changes once you consider the code stable (Sorry, I currently dont have the time to test this myself).

[Rappelbox]

I can confirm that there are no issues with the Teensy 4.0