2) Removed 'magic' constant 0.0044 from steering
computation; replaced by DEGREE_TO_RAD, which means
that steering values in stk_config.data and .kart files
have to be divided by about 3.9
3) Added early cancellation of parachute when a slow down
of 30% is reached (defined in stk_config.data). This allows
karts to brake and get rid of the parachute earlier.
git-svn-id: svn+ssh://svn.code.sf.net/p/supertuxkart/code/trunk/supertuxkart@1641 178a84e3-b1eb-0310-8ba1-8eac791a3b58