Remove "Current Password" input if mx_pass exists

If the user is PWLU, do not show "Current Password" field in ChangePassword and when setting a new password, use the cached password.

src/components/structures/LoggedInView.js

@@ -216,6 +216,7 @@ export default React.createClass({
                     enableLabs={this.props.config.enableLabs}
                     referralBaseUrl={this.props.config.referralBaseUrl}
                     teamToken={this.props.teamToken}
+                    cachedPassword={this.props.cachedPassword}
                 />;
                 if (!this.props.collapse_rhs) right_panel = <RightPanel opacity={this.props.sideOpacity}/>;
                 break;

src/components/structures/MatrixChat.js

@@ -590,6 +590,12 @@ module.exports = React.createClass({
                     payload.releaseNotes
                 );
                 break;
+            case 'password_changed':
+                this.setState({
+                    userHasGeneratedPassword: false,
+                });
+                localStorage.removeItem("mx_pass");
+                break;
         }
     },
 
@@ -1176,7 +1182,8 @@ module.exports = React.createClass({
                     onUserSettingsClose={this.onUserSettingsClose}
                     onRegistered={this.onRegistered}
                     teamToken={this._teamToken}
-                    userHasGeneratedPassword={this.state.userHasGeneratedPassword}
+                    cachedPassword={this.state.userHasGeneratedPassword ?
+                        localStorage.getItem('mx_pass') : null}
                     {...this.props}
                     {...this.state}
                 />

src/components/structures/UserSettings.js

@@ -139,6 +139,9 @@ module.exports = React.createClass({
         // Team token for the referral link. If falsy, the referral section will
         // not appear
         teamToken: React.PropTypes.string,
+
+        // the user is a PWLU (/w password stashed in localStorage 'mx_pass')
+        cachedPassword: React.PropTypes.string,
     },
 
     getDefaultProps: function() {
@@ -331,6 +334,7 @@ module.exports = React.createClass({
                           receive push notifications on other devices until you
                           log back in to them.`,
         });
+        dis.dispatch({action: 'password_changed'});
     },
 
     onUpgradeClicked: function() {
@@ -894,6 +898,7 @@ module.exports = React.createClass({
                         rowLabelClassName="mx_UserSettings_profileLabelCell"
                         rowInputClassName="mx_UserSettings_profileInputCell"
                         buttonClassName="mx_UserSettings_button mx_UserSettings_changePasswordButton"
+                        cachedPassword={this.props.cachedPassword}
                         onError={this.onPasswordChangeError}
                         onFinished={this.onPasswordChanged} />
             );