remove some valgrind suppression stuff that doesn't work on Linux
a packet is not complete if empty
Fix to generating readable MP4/MOV files:
* add Coder.get/setFlags, making sure setFlags cannot be done after
* open.
* make Muxer.addNewStream error out if the format requires global
* headers but the coder does not have that flag set.
* Regenerate necessary files.
* Various tests for good and error conditions.