Changes

Fix some VesselState thrust calculations (probably fix diffthrottle)

- Removes the double-cos-losses coming both from the cosineLosses variable
  and the vector addition by just dropping the cosineLosses variable.

- Change the CoT calculations to no longer be based on current thrust
  but on max thrust.  This ensures that ThrustForward is nonzero with
  zero thrust, and makes it a constant of the vessel geometry.  This
  means that diff throttle will also no longer affect and chase its
  own setpoint.  As I've been adding INERTIAL_COT to various
  controllers I've probably been breaking diffthrottle and this should
  fix that.

- That latter change might in principle break some badly constructed
  vehicles which have considerably different thrust vectors for
  minthrottle vs. maxthrottle for times when they aren't being
  max throttled.  As most things you want to do with rockets tend
  to be bang-bang control this shouldn't affect anyone, but to the
  extent it actually does affect anyone, those rockets and situations
  are just considered rocket design problems, and support is dropped.
 (commit: eae48a1)