Currently this would not be done if max_frames is triggered.
Makes no difference in either of the tools currently using
decode_simple, but may be important in future tools.
Frame counters can overflow relatively easily (INT_MAX number of frames is
slightly more than 1 year for 60 fps content), so make sure we use 64 bit
values for them.
Also deprecate the old 32 bit frame_number attribute.
Signed-off-by: Marton Balint <cus@passwd.hu>
