Removed VCT - use simple anglemod compensation instead

VCT results in really messed up video: the view would turn crazily, making it
very unpleasant to watch.  It also complicates matters without providing
measurable advantage.
Changed parsing of forwardmove, sidemove, upmove

The exact value of cl_forwardspeed, cl_sidespeed and cl_upspeed are no longer
important.  Just set them to 400 with different signs depending on direction.
In MOVEDATA, the exact value is no longer printed.
Removed anglemod_f and anglemod_c

They are required only by the VCT algorithm.
Changed the way pm_wishspeed is calculated

This also fixed the bug where pm_wishspeed has incorrect value when newly
ducked in the current frame.  Given that we no longer need to alter movespeeds,
newly_ducked is useless now.
Doc: move description of VC to appendix
Added run_sim, updated documentation
Basic implementation of tas_sa
Basic implementation of tas_s2y
Prevent tas_sa and tas_s2y strafing an extra frame
Clarify tas_s2y and tas_sa slightly in documentation
Merge branch 'novct'