Copter-4.0 updates to extended tuning screen

As part of the Copter-4.0 beta testing, we've noticed that a few fields on the Extended tuning page are blanked out because we've changed parameter names.


The TUNE_ parameters should be TUNE_MIN and TUNE_MAX (was TUNE_LOW, TUNE_HIGH)

For the Filters the single parameter for each axis has been replaced with 3 filters. So _FILT -> FLTE, FLTD and/or FLTT. After a discussion with @lthall we think it would be best if all three were shown.

@lthall is going to come up with some more input for this screen.

Start with the Extended tuning page and its existing parameter mappings. Check the TUNE_ and filter entries described in the issue; done means TUNE_MIN and TUNE_MAX display correctly and all three axis filter parameters—FLTE, FLTD, and FLTT—are shown.

Written by the indexing model from the issue text.