Merge a bunch of doxygen updates to header files. This includes changes to

use the \retval tag for documenting return values, fixing various warnings
when generating the documentation, and various other things.
(closes issue #10203, snuffy)


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@75164 65c4cc65-6c06-0410-ace0-fbb531ad65f3

include/asterisk/enum.h

@@ -52,7 +52,7 @@ struct enum_context {
 };
 
 
-/*! \brief Lookup entry in ENUM Returns 1 if found, 0 if not found, -1 on hangup
+/*! \brief Lookup entry in ENUM 
 	\param chan	Channel
 	\param number   E164 number with or without the leading +
 	\param location Number returned	(or SIP uri)
@@ -65,6 +65,9 @@ struct enum_context {
 	\param options  Options ('c' to count number of NAPTR RR)
 	\param record   The position of required RR in the answer list
 	\param argcontext   Argument for caching results into an enum_context pointer (NULL is used for not caching)
+	\retval 1 if found
+	\retval 0 if not found
+	\retval -1 on hangup
 */
 int ast_get_enum(struct ast_channel *chan, const char *number, char *location, int maxloc, char *technology, 
 		int maxtech, char* suffix, char* options, unsigned int record, struct enum_context **argcontext);