Interface extended to de-/prioritize value propagation and setting delay of frame cycle

[Pulsar07]

For sending about 20 telemetry values it is not sufficient to send/handle all values in the same manner, if the physical interface speed is limited (9600Baud).
It is very helpful if some values (variometer) are send more often than others (e.g.: number of satellites). This is provided by a changed set value methods, with additional prio parameters.
Furthermore the new SetJetiSendCycle()-method, allows setting a less delay time than the current hardcoded 150ms, to reduce value transmission delay to a minimum.
Tests with the VarioGPS-Sensor code was very promising.
Regards
Rainer

[Pulsar07]

Tests with more than 15 telemetry values (id > 15) forced problems. At the end a exBuf overflow forced the problems. Main problem was, that the buffer need one extra byte for id > 15 and the decision to handle one more value, was done on the wrong data, the bufLen of the current sensor and not of the next one.
So the preparation of the exBuf is reworked and works now without problems for all id.
Nevertheless there were problems sending some value of my variometer (rel. heigth in dcm). Analysis show, that on the workbench height of -1 dcm are send very often, but are ignored by the JetiExSensor.
I see no need for this behaviour, due to (now) exiting prio and disabling methods and the INVALID value -1 is now removed.

Regards Rainer