Prepare for asynchronous e2e APIs

the js-sdk is making some of its APIs asynchronous, and adding an `initCrypto`
method which you have to call.

Particular methods we need to worry about are:

* `getStoredDevice`
* `getStoredDevicesForUser`
* `getEventSenderDeviceInfo`
* `isEventSenderVerified`

src/components/views/rooms/EventTile.js

@@ -193,13 +193,12 @@ module.exports = withMatrixClient(React.createClass({
         }
     },
 
-    _verifyEvent: function(mxEvent) {
-        var verified = null;
-
-        if (mxEvent.isEncrypted()) {
-            verified = this.props.matrixClient.isEventSenderVerified(mxEvent);
+    _verifyEvent: async function(mxEvent) {
+        if (!mxEvent.isEncrypted()) {
+            return;
         }
 
+        const verified = await this.props.matrixClient.isEventSenderVerified(mxEvent);
         this.setState({
             verified: verified
         });

src/components/views/rooms/MemberInfo.js

@@ -136,8 +136,12 @@ module.exports = withMatrixClient(React.createClass({
         if (userId == this.props.member.userId) {
             // no need to re-download the whole thing; just update our copy of
             // the list.
-            var devices = this.props.matrixClient.getStoredDevicesForUser(userId);
-            this.setState({devices: devices});
+
+            // Promise.resolve to handle transition from static result to promise; can be removed
+            // in future
+            Promise.resolve(this.props.matrixClient.getStoredDevicesForUser(userId)).then((devices) => {
+                this.setState({devices: devices});
+            });
         }
     },
 
@@ -204,14 +208,15 @@ module.exports = withMatrixClient(React.createClass({
 
         var client = this.props.matrixClient;
         var self = this;
-        client.downloadKeys([member.userId], true).finally(function() {
+        client.downloadKeys([member.userId], true).then(() => {
+            return client.getStoredDevicesForUser(member.userId);
+        }).finally(function() {
             self._cancelDeviceList = null;
-        }).done(function() {
+        }).done(function(devices) {
             if (cancelled) {
                 // we got cancelled - presumably a different user now
                 return;
             }
-            var devices = client.getStoredDevicesForUser(member.userId);
             self._disambiguateDevices(devices);
             self.setState({devicesLoading: false, devices: devices});
         }, function(err) {