Niels Bogaards

Added Rewind and ReadNextSelectedFrame methods to Entity

removed many global variables, moved some into the thread-safe SdifGlobals structure, added HAVE_PTHREAD define, reorganized the code for selection, made some arguments const, new version 3.8.6

GetCol uses col increment instead of row increment

added time ouput format to extract only the times of selected frames

return zero if frame is not selected

isSelected function and corrections to the selection tests

check whether frame is high level selected is it is already in the framedir

readnextselectedframe in iterator dereference, fixed bool for isframeselected