BUG FIXES since the release of PLATFORMTRON 1.00

1.   a bug in TOworld::collision() which caused wrong collision
     detections. A pointer was increased by (len<<1) instead of (hei<<1)
2.   a bug in TOworld::make1bitmapdescr(). len * hei bytes of memory
     were allocated instead of (len+hei)<<1
3.   a bug in TOworld::sprintfdescr() (which now is named dprintf() )
     The memory allocated for a descriptor was freed but the descriptor
     was not NULLed. So the next call to getdescrmem() didn't allocate
     any memory and sprintfdescr() always failed.
4.   a bug in TOworld::makeframecolidmask(). This routine produced wrong
     collision masks because of wrong comparisons.
5.   a bug in TOworld::callactionfunctions() that caused PLTRON to enter
     a never ending loop, because the next entry of the list would not be
     taken if the current action function was not called.