Fix states mapping for Flap Load Relief.
Improve comments in aircraft tables constants.
Added CONF_VFE_NEXT_STATE to constants.
Fix some comments in aircraft table accessors.
Add support for looking up airbrake coefficients.
Add support for looking up VLS1g constants.
Add support for looking up flap manoeuvring speed tables.
[flake8] minor tidying.
Fixes and clean-ups for masked array test utils.
Overhaul velocity speed tables...

Fixes a number of issues and implements missing functionality.

- Add support for lookup by weight/altitude value or array.
- Gracefully handle masked values.
- Improve logging messages for issues in velocity speed tables.
- Split out fallback speed tables from the standard tables.
- Added weight_scale to velocity speed tables (for 1000 lb).
- Remove non-interpolation code paths from velocity speeds.
- Merge VMO/MMO lookup code into velocity speed tables.
- Remove maximum speed table accessors, tests, etc.
- Allow for fixed, stepped and interpolated VMO/MMO.
- Improve unit tests to be much more comprehensive.
Update documentation for velocity speeds.
Reorder arguments to get_vspeed_map().
Improve logging in vspeed table lookup.
Support unhashable types in memoize().
Restore v2/vref detent properties to VelocitySpeed.
Fix some incomplete/incorrect docstrings.
Tweak flap manoeuvring speed tables.
Fix: Use np.any() to allow comparison to list.

Prevents regression in some test cases.
Round velocity speeds (exc. MMO) to integer values.
Add missing accessors to __all__.