zero-copy msg_t::init cannot be used when the message exceeds either
the buffer end or the last received byte. To detect this, the buffer
is now resized to the numnber of received bytes.
Of course people still "can" distributed the sources under the
LGPLv3. However we provide COPYING.LESSER with additional grants.
Solution: specify these grants in the header of each source file.
* Command names changed from null terminated to length-specified
* Command frames use the correct flag (bit 2)
* test_stream acts as test case for command frames
* Some code cleanups
