Remove vmestream_transfer_data from servers

 - Use dedicated read/write functions instead
 - Do not use the VMEStream struct since that abstraction creates
   more difficulties than it solves.
Use dynamically allocated buffers
Remove references to 'stream'
vmestream_echo syntax fixes
Add comments and enhance formatting
Fix memory leaks in vme2fd
Comments and structuring for vmestream_echo
Don't block on input fifo
Fix newline for vmestream_echo printout
Merge branch 'vmestream_drop' into vmestream_dev