Log global errors

Use the global error handler, window.onerror, to catch miscellaneous
exceptions and pipe them into the debug log.

Fixes #456

// FREEBIE

js/debugLog.js

@@ -33,5 +33,9 @@
                 }).fail(resolve);
             });
         };
+
+        window.onerror = function(message, script, line, col, error) {
+            console.log(error);
+        };
     }
 })();

js/index.js

@@ -5,11 +5,22 @@
 (function () {
     'use strict';
 
+    function logError(error) {
+        extension.windows.getBackground(function(bg) {
+            bg.console.log('index.html: ', error);
+        });
+    }
+
+    window.onerror = function(message, script, line, col, error) {
+        logError(error);
+    };
+
     var view;
 
     function render() {
         extension.windows.getBackground(function(bg) {
             extension.windows.getCurrent(function(appWindow) {
+                try {
                     if (view) { view.remove(); }
                     var $body = bg.$('body',document).empty();
                     view = new bg.Whisper.InboxView({appWindow: appWindow});
@@ -20,6 +31,10 @@
                         }
                     };
                     openConversation(bg.getOpenConversation());
+                } catch (e) {
+                    logError(e);
+                }
+
             });
         });
     }