Fix incoming key conflict behaviors

Follow up to ddd2e67eb5
but for incoming messages.

* Conflict state sometimes failed to be removed even though the
  conflict was resolved.
* Messages failed to re-render after a conflict. We want to
  re-render only the error state on outgoing messages, to avoid
  flickering attachments. On incoming messages, we need to call
  render to populate the message text, avatar, etc...

// FREEBIE

js/models/messages.js

@@ -202,6 +202,7 @@
                 var promise = new textsecure.ReplayableError(error).replay();
                 if (this.isIncoming()) {
                     promise = promise.then(function(dataMessage) {
+                        this.removeConflictFor(number);
                         this.handleDataMessage(dataMessage);
                     }.bind(this));
                 } else {

js/views/message_view.js

@@ -9,7 +9,7 @@
         tagName:   "li",
         template: $('#message').html(),
         initialize: function() {
-            this.listenTo(this.model, 'change:errors', this.renderErrors);
+            this.listenTo(this.model, 'change:errors', this.onErrorsChanged);
             this.listenTo(this.model, 'change:body', this.render);
             this.listenTo(this.model, 'change:delivered', this.renderDelivered);
             this.listenTo(this.model, 'change', this.renderSent);
@@ -44,6 +44,13 @@
         renderDelivered: function() {
             if (this.model.get('delivered')) { this.$el.addClass('delivered'); }
         },
+        onErrorsChanged: function() {
+            if (this.model.isIncoming()) {
+                this.render();
+            } else {
+                this.renderErrors();
+            }
+        },
         renderErrors: function() {
             var errors = this.model.get('errors');
             if (_.size(errors) > 0) {