Move keyboard focus management back to the BaseDialog rather than

leaving it in the Modal manager.
We are using Modal manager to load other components not just BaseDialog
and its subclasses and they might require different keyboard handling.
Also depend on focus-trap-react rather than react-focus-trap for locking
keyboard focus inside the dialog. The experience is much nicer and even
the FocusTrap element it-self no longer gains the focus.
On a side note using the FocusTrap element outside the dialog (on
its parent) stops it from working properly.

src/components/views/dialogs/BaseDialog.js

@@ -15,6 +15,7 @@ limitations under the License.
 */
 
 import React from 'react';
+import FocusTrap from 'focus-trap-react';
 
 import * as KeyCode from '../../../KeyCode';
 import AccessibleButton from '../elements/AccessibleButton';
@@ -61,6 +62,14 @@ export default React.createClass({
         }
     },
 
+    _onKeyDown: function(e) {
+        if (e.keyCode === KeyCode.ESCAPE) {
+            e.stopPropagation();
+            e.preventDefault();
+            this.props.onFinished();
+        }
+    },
+
     _onCancelClick: function(e) {
         this.props.onFinished();
     },
@@ -69,7 +78,7 @@ export default React.createClass({
         const TintableSvg = sdk.getComponent("elements.TintableSvg");
 
         return (
-            <div className={this.props.className} role="dialog" aria-labelledby='mx_BaseDialog_title' aria-describedby={this.props.contentId}>
+            <FocusTrap onKeyDown={this._onKeyDown} className={this.props.className} role="dialog" aria-labelledby='mx_BaseDialog_title' aria-describedby={this.props.contentId}>
                 <AccessibleButton onClick={this._onCancelClick}
                     className="mx_Dialog_cancelButton"
                 >
@@ -79,7 +88,7 @@ export default React.createClass({
                     { this.props.title }
                 </div>
                 { this.props.children }
-            </div>
+            </FocusTrap>
         );
     },
 });