[Views] Update representations on mutation (#1312)

* [Core] Log errors from topic

Log full error (including stack trace) when catching errors
from the topic service. Aids debugging of #1303 (and should
aid in future debugging of any similar issues.)

* [API] Fix identifier usage in handleMutation

To address console errors observed in the context of #1303

* [Views] Listen to mutation

Listen for mutation instead of watching modified timestamp;
more reliable due to recent API changes. Fixes #1303.

* [Views] Update spec for mct-representation

...to reflect changes for #1303

platform/core/src/services/Topic.js

@@ -67,6 +67,7 @@ define(
                                 listener(message);
                             } catch (e) {
                                 $log.error(ERROR_PREFIX + e.message);
+                                $log.error(e);
                             }
                         });
                     }