classes for recording and for replaying. Added compression (by use of
interpolation) settings to stk_config - atm only using a certain
frequency (delta-t setting in stk_config) is used.
git-svn-id: svn+ssh://svn.code.sf.net/p/supertuxkart/code/main/trunk@10904 178a84e3-b1eb-0310-8ba1-8eac791a3b58