Add API allowing xAPPs to send alarm messages

This change adds the ability for an xAPP to send alarms to
the alarm collector/manager via RMR messages.

This is a BREAKING change because the C++ framework classes
are all now wrapped in the xapp:: namespace.

Issue-ID: RIC-426

Signed-off-by: E. Scott Daniels <daniels@research.att.com>
Change-Id: I552292d57e987313ec684bd55f8780ef5fba74fe
diff --git a/src/messaging/default_cb.cpp b/src/messaging/default_cb.cpp
index 1083293..2156ad3 100644
--- a/src/messaging/default_cb.cpp
+++ b/src/messaging/default_cb.cpp
@@ -38,6 +38,9 @@
 
 #include "messenger.hpp"
 
+namespace xapp {
+
+
 /*
 	This is the default health check function that we provide (user
 	may override it).  It will respond to health check messages by
@@ -52,3 +55,6 @@
 	snprintf( (char* ) response, sizeof( response ), "OK\n" );
 	mbuf.Send_response( RIC_HEALTH_CHECK_RESP, sid, strlen( (char *) response )+1, response );
 }
+
+
+} // namespace