fix socket communication protocol between firmware and server (wait for ok on EAGAIN)
separate out general buffer handling, direct file handling, and relfile handling
Some cleanup, especially more cmds separated out into their own functions in fscmd.c
fix test for wrong message
Fix block commands in di_provider
Fix block handling - all tests work (believing af1 and af2 on 4040 are actual DOS bugs)
investigate af1/af2 block tests; improve diff on test files for fwtests