add missing copyright statements to source code files

Some source code files didn't have the usual copyright and licence
statement at their top.  I'm adding them baesed on information in the
commitlog.
diff --git a/src/bits.c b/src/bits.c
index 6be6d7a..01d7e73 100644
--- a/src/bits.c
+++ b/src/bits.c
@@ -1,3 +1,24 @@
+/*
+ * (C) 2011 by Harald Welte <laforge@gnumonks.org>
+ * (C) 2011 by Sylvain Munaut <tnt@246tNt.com>
+ *
+ * All Rights Reserved
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ */
 
 #include <stdint.h>
 
diff --git a/src/gsm/tlv_parser.c b/src/gsm/tlv_parser.c
index 8cb2139..5eee53a 100644
--- a/src/gsm/tlv_parser.c
+++ b/src/gsm/tlv_parser.c
@@ -1,3 +1,22 @@
+/* (C) 2008-2010 by Harald Welte <laforge@gnumonks.org>
+ *
+ * All Rights Reserved
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
 #include <stdio.h>
 #include <stdint.h>
 #include <osmocom/core/utils.h>
diff --git a/src/macaddr.c b/src/macaddr.c
index f6b1ebb..7bc4401 100644
--- a/src/macaddr.c
+++ b/src/macaddr.c
@@ -1,3 +1,25 @@
+/*
+ * (C) 2013-2014 by Harald Welte <laforge@gnumonks.org>
+ * (C) 2014 by Holger Hans Peter Freyther
+ *
+ * All Rights Reserved
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ */
+
 #include <stdint.h>
 #include <string.h>
 #include <stdlib.h>
diff --git a/src/socket.c b/src/socket.c
index c93224a..844ebd3 100644
--- a/src/socket.c
+++ b/src/socket.c
@@ -1,3 +1,24 @@
+/*
+ * (C) 2011 by Harald Welte <laforge@gnumonks.org>
+ *
+ * All Rights Reserved
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ */
+
 #include "../config.h"
 
 /*! \addtogroup socket
diff --git a/src/utils.c b/src/utils.c
index cc33994..6ece1a8 100644
--- a/src/utils.c
+++ b/src/utils.c
@@ -1,3 +1,26 @@
+/*
+ * (C) 2011 by Harald Welte <laforge@gnumonks.org>
+ * (C) 2011 by Sylvain Munaut <tnt@246tNt.com>
+ * (C) 2014 by Nils O. Selåsdal <noselasd@fiane.dyndns.org>
+ *
+ * All Rights Reserved
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ */
+
 
 #include <string.h>
 #include <stdint.h>