Widespread minor changes to eliminate the use of SDL_GetTicks to

Widespread minor changes to eliminate the use of SDL_GetTicks to
determine the current time.  Pass it as paint argument instead to allow
billboards and coins to spin correctly in uniform mode.
Also, eliminated obsolete stereo separation paint argument.

git-svn-id: https://s.snth.net/svn/neverball/trunk@1618 78b8d119-cf0a-0410-b17c-f493084dd1d7