Sending an SR_DF_META packet at the start of every stream is not
mandatory; the frontend should ask for what it needs, and any extra
information the driver wants to send will come in due time.
Fix the bare minumum of whitespace/indentation/coding-style via
automatic 'indent' run, followed by some minor manual fixes.
Some more fixes and cleanups might follow later.
Bring back the original (C) lines from before the split into api.c
and protocol.[ch].
Add "Copyright (C) 2013 Lior Elazary <lelazary@yahoo.com>" since there
were nontrivial changes to those files.