Add a forget button. Add left rooms to the "historical" tab.

Call /forget when the forget button is clicked. Number of shortcomings:
 - We need to lazy load the historical list (atm we never get the list of left
   rooms; things only go into that list if you leave the room whilst running)
 - Once a room is forgotten we need to physically nuke it from the JS SDK.
 - Need icon for forget room.

src/components/structures/RoomView.js

@@ -824,7 +824,14 @@ module.exports = React.createClass({
             action: 'leave_room',
             room_id: this.props.roomId,
         });
-        this.props.onFinished();        
+    },
+
+    onForgetClick: function() {
+        MatrixClientPeg.get().forget(this.props.roomId).done(function() {
+            dis.dispatch({ action: 'view_next_room' });
+        }, function(err) {
+            console.error("Failed to forget room: %s", err);
+        });
     },
 
     onRejectButtonClicked: function(ev) {
@@ -1249,8 +1256,18 @@ module.exports = React.createClass({
 
             return (
                 <div className={ "mx_RoomView" + (inCall ? " mx_RoomView_inCall" : "") }>
-                    <RoomHeader ref="header" room={this.state.room} searchInfo={searchInfo} editing={this.state.editingRoomSettings} onSearchClick={this.onSearchClick}
+                    <RoomHeader ref="header" room={this.state.room} searchInfo={searchInfo}
-                        onSettingsClick={this.onSettingsClick} onSaveClick={this.onSaveClick} onCancelClick={this.onCancelClick} onLeaveClick={this.onLeaveClick} />
+                        editing={this.state.editingRoomSettings}
+                        onSearchClick={this.onSearchClick}
+                        onSettingsClick={this.onSettingsClick}
+                        onSaveClick={this.onSaveClick}
+                        onCancelClick={this.onCancelClick}
+                        onForgetClick={
+                            (myMember && myMember.membership === "leave") ? this.onForgetClick : null
+                        }
+                        onLeaveClick={
+                            (myMember && myMember.membership === "join") ? this.onLeaveClick : null
+                        } />
                     { fileDropTarget }    
                     <div className="mx_RoomView_auxPanel">
                         <CallView ref="callView" room={this.state.room} ConferenceHandler={this.props.ConferenceHandler}/>

src/components/views/rooms/RoomHeader.js

@@ -129,7 +129,17 @@ module.exports = React.createClass({
             if (this.props.onLeaveClick) {
                 leave_button =
                     <div className="mx_RoomHeader_button mx_RoomHeader_leaveButton">
-                        <img src="img/leave.svg" title="Leave room" alt="Leave room" width="26" height="20" onClick={this.props.onLeaveClick}/>
+                        <img src="img/leave.svg" title="Leave room" alt="Leave room"
+                            width="26" height="20" onClick={this.props.onLeaveClick}/>
+                    </div>;
+            }
+
+            var forget_button;
+            if (this.props.onForgetClick) {
+                forget_button =
+                    <div className="mx_RoomHeader_button mx_RoomHeader_leaveButton">
+                        <img src="img/leave.svg" title="Forget room" alt="Forget room"
+                            width="26" height="20" onClick={this.props.onForgetClick}/>
                     </div>;
             }
 
@@ -147,6 +157,7 @@ module.exports = React.createClass({
                     {cancel_button}
                     {save_button}
                     <div className="mx_RoomHeader_rightRow">
+                        { forget_button }
                         { leave_button }
                         <div className="mx_RoomHeader_button">
                             <img src="img/search.svg" title="Search" alt="Search" width="21" height="19" onClick={this.props.onSearchClick}/>

src/components/views/rooms/RoomList.js

@@ -168,6 +168,9 @@ module.exports = React.createClass({
             if (me && me.membership == "invite") {
                 s.lists["im.vector.fake.invite"].push(room);
             }
+            else if (me && (me.membership === "leave" || me.membership === "ban")) {
+                s.lists["im.vector.fake.archived"].push(room);
+            }
             else {
                 var shouldShowRoom =  (
                     me && (me.membership == "join")