decision to split
finished writing, not debugged

Got the new from-scratch trim function written, and it runs.  But it's
not right at all.  Not debugged or anything, and the iteration just
runs.  The angle definitions are not correct.
End of feb 13 work

Still debugging.  Got it to kind of start converging, so there may be
hope for this routine.  Need to check all my angle definitions and sign
conventions.  Also figure out how I'm going to alter the controls.
removed a useless stub?
converting detailed blade element to partiall-derived equations
got it running
end of work, feb 18
IT WORKS!

All right, it's actually working and seems to be robust!  Added in
another c81 file and did some basic tests.  Everything seems to be good.
Partially incorporated the BEMT into vehicle.py, but it doesn't use all
the config values at the moment, so that'll have to be fixed, and
everything will have to be switched over to BEMT and momentum theory
removed.  It even runs quickly!  I'd like to tweak the tolerances and
differentials (or better yet, put them in the config) to try to improve
speed even further.  But the main thing is fully integrating it and
making sure all the config values are consistent etc., plus doing full
validation.
BEMT total conversion

fully integrated BEMT.  Nonuniform inflow.  No tip losses yet.  Flexible
with config.  Having trouble with the mission sizing and am going to
switch to running the mission forwards; the simple version.  Also need
to decide how to handle untrimmable vehicles in the rf process.
Switched to forward mission calculations

Seems to be working fine
cleaned up a couple things
more cleanup
fixed BEMT power problem

blade element thrust and drag was not normalized to the whole rotor
disk.  Fixed now.
getting good

dealt with untrimmable vehicles in rf.py, added a couple new outputs,
and added a tip loss model.
end of day, feb 20

Still tweaking.  There seems to be something wrong with the wing, maybe.
Between that and the aux propulsion, I feel like I should be able to
trim at high speeds, but I'm not able to.  Will have to experiment in
those ranges tomorrow.
drag divergence added

Added in basic drag divergence with mach number calculation
partially validated

did some validation, general cleanup, added in some performance
calculations.
created design space generation tool
two bug fixes

Fixed a bug where missoin segment data was being ignored.
Also, a vehicle which can never be trimmed results in NaN as
SizedGrossWeight.
moved parasite power from BEMT to vehicle

parasite power was previously included per-rotor accidentally.  Moved to
vehicle powerReq().  Also any new Vehicle now creates a copy of the
configs it is passed, rather than operating on the originals.