doxygen: unify use of \file across the board

Considering the various styles and implications found in the sources, edit
scores of files to follow the same API doc guidelines around the doxygen
grouping and the \file tag.

Many files now show a short description in the generated API doc that was so
far only available as C comment.

The guidelines and reasoning behind it is documented at
https://osmocom.org/projects/cellular-infrastructure/wiki/Guidelines_for_API_documentation

In some instances, remove file comments and add to the corresponding group
instead, to be shared among several files (e.g. bitvec).

Change-Id: Ifa70e77e90462b5eb2b0457c70fd25275910c72b
diff --git a/include/osmocom/gprs/gprs_bssgp.h b/include/osmocom/gprs/gprs_bssgp.h
index 0e9f7d6..2dead69 100644
--- a/include/osmocom/gprs/gprs_bssgp.h
+++ b/include/osmocom/gprs/gprs_bssgp.h
@@ -1,3 +1,5 @@
+/*! \file gprs_bssgp.h */
+
 #pragma once
 
 #include <stdint.h>
diff --git a/include/osmocom/gprs/gprs_bssgp_bss.h b/include/osmocom/gprs/gprs_bssgp_bss.h
index d79b210..9374e73 100644
--- a/include/osmocom/gprs/gprs_bssgp_bss.h
+++ b/include/osmocom/gprs/gprs_bssgp_bss.h
@@ -1,11 +1,7 @@
-#pragma once
-
-#include <osmocom/core/msgb.h>
-#include <osmocom/gprs/gprs_bssgp.h>
-
-/* GPRS BSSGP protocol implementation as per 3GPP TS 08.18 */
-
-/* (C) 2009-2012 by Harald Welte <laforge@gnumonks.org>
+/*! \file gprs_bssgp_bss.h
+ * GPRS BSSGP protocol implementation as per 3GPP TS 08.18 */
+/*
+ * (C) 2009-2012 by Harald Welte <laforge@gnumonks.org>
  *
  * All Rights Reserved
  *
@@ -24,6 +20,10 @@
  *
  */
 
+#pragma once
+
+#include <osmocom/core/msgb.h>
+#include <osmocom/gprs/gprs_bssgp.h>
 
 uint8_t *bssgp_msgb_tlli_put(struct msgb *msg, uint32_t tlli);
 
diff --git a/include/osmocom/gprs/gprs_msgb.h b/include/osmocom/gprs/gprs_msgb.h
index 9ccc9a5..43471e2 100644
--- a/include/osmocom/gprs/gprs_msgb.h
+++ b/include/osmocom/gprs/gprs_msgb.h
@@ -1,3 +1,5 @@
+/*! \file gprs_msgb.h */
+
 #pragma once
 
 #include <stdint.h>
diff --git a/include/osmocom/gprs/gprs_ns.h b/include/osmocom/gprs/gprs_ns.h
index 5ecaed8..938ad99 100644
--- a/include/osmocom/gprs/gprs_ns.h
+++ b/include/osmocom/gprs/gprs_ns.h
@@ -1,3 +1,5 @@
+/*! \file gprs_ns.h */
+
 #pragma once
 
 #include <stdint.h>
diff --git a/include/osmocom/gprs/gprs_ns_frgre.h b/include/osmocom/gprs/gprs_ns_frgre.h
index 72ef7d1..d48ce08 100644
--- a/include/osmocom/gprs/gprs_ns_frgre.h
+++ b/include/osmocom/gprs/gprs_ns_frgre.h
@@ -1,3 +1,5 @@
+/*! \file gprs_ns_frgre.h */
+
 #pragma once
 
 int gprs_ns_frgre_sendmsg(struct gprs_nsvc *nsvc, struct msgb *msg);
diff --git a/include/osmocom/gprs/gprs_rlc.h b/include/osmocom/gprs/gprs_rlc.h
index 5765281..05d3de6 100644
--- a/include/osmocom/gprs/gprs_rlc.h
+++ b/include/osmocom/gprs/gprs_rlc.h
@@ -1,3 +1,5 @@
+/*! \file gprs_rlc.h */
+
 #pragma once
 
 #include <stdint.h>
diff --git a/include/osmocom/gprs/protocol/gsm_04_60.h b/include/osmocom/gprs/protocol/gsm_04_60.h
index 42028bd..96e9ab7 100644
--- a/include/osmocom/gprs/protocol/gsm_04_60.h
+++ b/include/osmocom/gprs/protocol/gsm_04_60.h
@@ -1,10 +1,11 @@
-#pragma once
-
-/* General Packet Radio Service (GPRS)
+/*! \file gsm_04_60.h
+ * General Packet Radio Service (GPRS).
  * Radio Link Control / Medium Access Control (RLC/MAC) protocol
  * 3GPP TS 04.60 version 8.27.0 Release 1999
  */
 
+#pragma once
+
 #include <stdint.h>
 
 #if OSMO_IS_LITTLE_ENDIAN == 1
diff --git a/include/osmocom/gprs/protocol/gsm_08_16.h b/include/osmocom/gprs/protocol/gsm_08_16.h
index c3dbe69..fc74336 100644
--- a/include/osmocom/gprs/protocol/gsm_08_16.h
+++ b/include/osmocom/gprs/protocol/gsm_08_16.h
@@ -1,16 +1,15 @@
-#pragma once
-
-/* GPRS Networks Service (NS) messages on the Gb interface
+/*! \file gsm_08_16.h
+ * GPRS Networks Service (NS) messages on the Gb interface.
  * 3GPP TS 08.16 version 8.0.1 Release 1999 / ETSI TS 101 299 V8.0.1 (2002-05)
  * 3GPP TS 48.016 version 6.5.0 Release 6 / ETSI TS 148 016 V6.5.0 (2005-11) */
 
+#pragma once
+
 #include <stdint.h>
 
 /*! \addtogroup libgb
  *  @{
- */
-
-/*! \file gprs_ns.h */
+ * \file gprs_ns.h */
 
 /*! Common header of GPRS NS */
 struct gprs_ns_hdr {
diff --git a/include/osmocom/gprs/protocol/gsm_08_18.h b/include/osmocom/gprs/protocol/gsm_08_18.h
index 8bc9a8e..3179455 100644
--- a/include/osmocom/gprs/protocol/gsm_08_18.h
+++ b/include/osmocom/gprs/protocol/gsm_08_18.h
@@ -1,3 +1,5 @@
+/*! \file gsm_08_18.h */
+
 #pragma once
 
 #include <stdint.h>