Improve chat column behavior for newline in empty text box

Summary: Ref T7538. I got this half correct but not fully correct: when you press enter in an empty text box, do nothing (instead of: sending an empty message, or writing a literal newline).

Test Plan: Hit enter in empty chat column box.

Reviewers: btrahan, chad

Reviewed By: chad

Subscribers: epriestley

Maniphest Tasks: T7538

Differential Revision: https://secure.phabricator.com/D12089

resources/celerity/map.php

@@ -353,7 +353,7 @@ return array(
     'rsrc/js/application/auth/behavior-persona-login.js' => '9414ff18',
     'rsrc/js/application/config/behavior-reorder-fields.js' => '14a827de',
     'rsrc/js/application/conpherence/ConpherenceThreadManager.js' => 'cff1902b',
-    'rsrc/js/application/conpherence/behavior-durable-column.js' => '332ac18d',
+    'rsrc/js/application/conpherence/behavior-durable-column.js' => 'e975bd12',
     'rsrc/js/application/conpherence/behavior-menu.js' => 'c4151295',
     'rsrc/js/application/conpherence/behavior-pontificate.js' => '21ba5861',
     'rsrc/js/application/conpherence/behavior-quicksand-blacklist.js' => '7927a7d3',
@@ -583,7 +583,7 @@ return array(
     'javelin-behavior-diffusion-locate-file' => '6d3e1947',
     'javelin-behavior-diffusion-pull-lastmodified' => '2b228192',
     'javelin-behavior-doorkeeper-tag' => 'e5822781',
-    'javelin-behavior-durable-column' => '332ac18d',
+    'javelin-behavior-durable-column' => 'e975bd12',
     'javelin-behavior-error-log' => '6882e80a',
     'javelin-behavior-fancy-datepicker' => 'c51ae228',
     'javelin-behavior-global-drag-and-drop' => 'bbdf75ca',
@@ -1054,16 +1054,6 @@ return array(
     '331b1611' => array(
       'javelin-install',
     ),
-    '332ac18d' => array(
-      'javelin-behavior',
-      'javelin-dom',
-      'javelin-stratcom',
-      'javelin-behavior-device',
-      'javelin-scrollbar',
-      'javelin-quicksand',
-      'phabricator-keyboard-shortcut',
-      'conpherence-thread-manager',
-    ),
     '3ab51e2c' => array(
       'javelin-behavior',
       'javelin-behavior-device',
@@ -1903,6 +1893,16 @@ return array(
       'javelin-dom',
       'phabricator-draggable-list',
     ),
+    'e975bd12' => array(
+      'javelin-behavior',
+      'javelin-dom',
+      'javelin-stratcom',
+      'javelin-behavior-device',
+      'javelin-scrollbar',
+      'javelin-quicksand',
+      'phabricator-keyboard-shortcut',
+      'conpherence-thread-manager',
+    ),
     'ea681761' => array(
       'javelin-behavior',
       'javelin-aphlict',