This adds copyright notes to all non-trivial source files,
unless they where already there (i.e. dev/endpoint.c alone).

I found authorship using the following script, run on commit "a2721762


documentation updated" (i.e, before automatic reindentation and other
trivial stuff by me):

  git grep -l . | grep -v sockitowm/ | \
  while read F; do
       echo "##### $F"
       git blame -w $F | \
         sed -e 's/^[^ ]* .//' -e 's/-[0-9][0-9]-[0-9][0-9] .*$//' | \
         sort | uniq -c | sort -rn
  done

Then I augmented each file with this boilerplate:

/*
 * This work is part of the White Rabbit project
 *
 * Copyright (C) 2011 CERN (www.cern.ch)
 * Copyright (C) 2011,2012 CERN (www.cern.ch)
 * Copyright (C) 2012 CERN (www.cern.ch)
 * Copyright (C) 2011 GSI (www.gsi.de)
 * Copyright (C) 2011,2012 GSI (www.gsi.de)
 * Copyright (C) 2012 GSI (www.gsi.de)
 * Author: Tomasz Wlostowski <tomasz.wlostowski@cern.ch>
 * Author: Grzegorz Daniluk <grzegorz.daniluk@cern.ch>
 * Author: Wesley W. Terpstra <w.terpstra@gsi.de>
 *
 * Released according to the GNU GPL, version 2 or any later version.
 */

Then I removed all the lines that didn't apply. Sometimes I reordered
the authors to reflect who is the main author.

Signed-off-by: Alessandro Rubini <rubini@gnudd.com>