Pretty-print "msg" when task fails

Several modules (e.g., pip) return stdout and stderr together in a "msg" variable (and the module development docs seem to suggest that the standard practice is to return status in this variable).

This change ensures that it is printed out with correct formatting (most importantly, with newlines appearing as newlines instead of \n).

lib/ansible/callbacks.py

@@ -314,6 +314,7 @@ class PlaybookRunnerCallbacks(DefaultRunnerCallbacks):
             module_msg  = results2.pop('msg', None)
         stderr = results2.pop('stderr', None)
         stdout = results2.pop('stdout', None)
+        returned_msg = results2.pop('msg', None)
 
         if item:
             msg = "failed: [%s] => (item=%s) => %s" % (host, item, utils.jsonify(results2))
@@ -325,6 +326,8 @@ class PlaybookRunnerCallbacks(DefaultRunnerCallbacks):
             print stringc("stderr: %s" % stderr, 'red')
         if stdout:
             print stringc("stdout: %s" % stdout, 'red')
+        if returned_msg:
+            print stringc("msg: %s" % returned_msg, 'red')
         if not parsed and module_msg:
             print stringc("invalid output was: %s" % module_msg, 'red')
         if ignore_errors: