doxygen: enable AUTOBRIEF, drop \brief

Especially for short descriptions, it is annoying to have to type \brief for
every single API doc.

Drop all \brief and enable the AUTOBRIEF feature of doxygen, which always takes
the first sentence of an API doc as the brief description.

Change-Id: I11a8a821b065a128108641a2a63fb5a2b1916e87
diff --git a/src/vty/command.c b/src/vty/command.c
index 0168462..a0824d3 100644
--- a/src/vty/command.c
+++ b/src/vty/command.c
@@ -43,7 +43,7 @@
 
 /*! \addtogroup command
  *  @{
- *  \brief VTY command handling
+ *  VTY command handling
  */
 /*! \file command.c */
 
@@ -88,7 +88,7 @@
 /* Default motd string. */
 const char *default_motd = "";
 
-/*! \brief print the version (and optionally copyright) information
+/*! print the version (and optionally copyright) information
  *
  * This is called from main when a daemon is invoked with -v or --version. */
 void print_version(int print_copyright)
@@ -123,7 +123,7 @@
 	return str;
 }
 
-/*! \brief Install top node of command vector. */
+/*! Install top node of command vector. */
 void install_node(struct cmd_node *node, int (*func) (struct vty *))
 {
 	vector_set_index(cmdvec, node->node, node);
@@ -160,7 +160,7 @@
 		return vty->node > CONFIG_NODE;
 }
 
-/*! \brief Sort each node's command element according to command string. */
+/*! Sort each node's command element according to command string. */
 void sort_node(void)
 {
 	unsigned int i, j;
@@ -240,7 +240,7 @@
 	}
 }
 
-/*! \brief Free allocated string vector. */
+/*! Free allocated string vector. */
 void cmd_free_strvec(vector v)
 {
 	unsigned int i;
@@ -256,7 +256,7 @@
 	vector_free(v);
 }
 
-/*! \brief Fetch next description.  Used in \ref cmd_make_descvec(). */
+/*! Fetch next description.  Used in \ref cmd_make_descvec(). */
 static char *cmd_desc_str(const char **string)
 {
 	const char *cp, *start;
@@ -291,7 +291,7 @@
 	return token;
 }
 
-/*! \brief New string vector. */
+/*! New string vector. */
 static vector cmd_make_descvec(const char *string, const char *descstr)
 {
 	int multiple = 0;
@@ -394,7 +394,7 @@
 	return size;
 }
 
-/*! \brief Return prompt character of specified node. */
+/*! Return prompt character of specified node. */
 const char *cmd_prompt(enum node_type node)
 {
 	struct cmd_node *cnode;
@@ -404,7 +404,7 @@
 }
 
 /*!
- * \brief escape all special asciidoc symbols
+ * escape all special asciidoc symbols
  * \param unsafe string
  * \return a new talloc char *
  */
@@ -595,7 +595,7 @@
 	return 0;
 }
 
-/* \brief Check if a command with given string exists at given node */
+/* Check if a command with given string exists at given node */
 static int check_element_exists(struct cmd_node *cnode, const char *cmdstring)
 {
 	int i;
@@ -611,7 +611,7 @@
 	return 0;
 }
 
-/*! \brief Install a command into a node
+/*! Install a command into a node
  *  \param[in] ntype Node Type
  *  \param[cmd] element to be installed
  */
@@ -3406,7 +3406,7 @@
 }
 
 /**
- * \brief Write the current running config to a given file
+ * Write the current running config to a given file
  * \param[in] vty the vty of the code
  * \param[in] filename where to store the file
  * \return 0 in case of success.
@@ -3426,7 +3426,7 @@
 }
 
 /**
- * \brief Save the current state to the config file
+ * Save the current state to the config file
  * \return 0 in case of success.
  *
  * If the filename already exists create a filename.sav