Define variable step tumb

[jdahlblom]

This will add it to Module and unit tests. Needed for F5-E3-3.

[charliefoxtwo]

If this is only used in the F5, I'd suggest just leaving it in the F5 file. I think there are one or two other modules that have custom controls defined in the module file.

I haven't been worrying about tests for these one-off controls. In the future I'd like to expand the aircraft tests to test the specific getters and these custom controls, but I think that's a lower priority right now.

[jdahlblom]

This will add it to Module and unit tests.

If this is only used in the F5, I'd suggest just leaving it in the F5 file. I think there are one or two other modules that have custom controls defined in the module file.

I haven't been worrying about tests for these one-off controls. In the future I'd like to expand the aircraft tests to test the specific getters and these custom controls, but I think that's a lower priority right now.

IT is used in 5 modules.