message: add copyright statement
diff: +/*
  + * Copyright (c) 2017, Daniel Krebs, RWTH Aachen University
  + * All rights reserved.
  + *
  + * Redistribution and use in source and binary forms, with or without
  + * modification, are permitted provided that the following conditions are met:
  + * * Redistributions of source code must retain the above copyright
  + * notice, this list of conditions and the following disclaimer.
  + * * Redistributions in binary form must reproduce the above copyright
  + * notice, this list of conditions and the following disclaimer in the
  + * documentation and/or other materials provided with the distribution.
  + * * Neither the name of the University nor the names of its contributors
  + * may be used to endorse or promote products derived from this
  + * software without specific prior written permission.
  + *
  + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
  + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
  + * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  + * DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE FOR ANY
  + * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
  + * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  + * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
  + * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
  + * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  + */
  #include <hermit/signal.h>
  #include <hermit/stddef.h>
  #include <hermit/spinlock.h>
  @@ -196,4 +222,3 @@ void signal_init()
  irq_install_handler(SIGNAL_IRQ, _signal_irq_handler);
  }
  -
  