Add Doxygen documentation for API changes from 1.6.0 to 1.6.1

Copied from my review board description:
This is a continuation of the API changes documentation started for describing
changes between releases. Most of the API changes were pretty simple needing
only to be brought to attention via the new "Asterisk API Changes" list.
However, if you see anything that needs further explanation feel free to
supplement what is there. The current method of documenting is to add (in the
header file): \version <ver number> <description of changes> and then to add
the function to the change list in doxyref.h on the AstAPIChanges page. I also
made sure all the functions that were newly added were tagged with \since
1.6.1. I think this is a good habit to start both for the historical aspect as
well as for the future ability to easily add a "New Asterisk API" page.

Review: http://reviewboard.digium.com/r/190/


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@180719 65c4cc65-6c06-0410-ace0-fbb531ad65f3

include/asterisk/tcptls.h

@@ -149,10 +149,27 @@ struct ast_tcptls_session_instance {
 #define LEN_T size_t
 #endif
 
+/*!
+ * \brief A generic client routine for a TCP client
+ * and starts a thread for handling accept()
+ * \version 1.6.1 changed desc parameter to be of ast_tcptls_session_args type
+ */
 struct ast_tcptls_session_instance *ast_tcptls_client_start(struct ast_tcptls_session_args *desc);
 
 void *ast_tcptls_server_root(void *);
+
+/*!
+ * \brief This is a generic (re)start routine for a TCP server,
+ * which does the socket/bind/listen and starts a thread for handling
+ * accept().
+ * \version 1.6.1 changed desc parameter to be of ast_tcptls_session_args type
+ */
 void ast_tcptls_server_start(struct ast_tcptls_session_args *desc);
+
+/*!
+ * \brief Shutdown a running server if there is one
+ * \version 1.6.1 changed desc parameter to be of ast_tcptls_session_args type
+ */
 void ast_tcptls_server_stop(struct ast_tcptls_session_args *desc);
 int ast_ssl_setup(struct ast_tls_config *cfg);