Added docs around MapLock, change visibility of methods

Removed unused global

control.go

@@ -64,7 +64,7 @@ func (c *Controller) StartGame(w http.ResponseWriter, req *http.Request) {
 		mode = cfg.Mode
 	}
 
-	g := c.Games.get(requested_game_name)
+	g := c.Games.Get(requested_game_name)
 	if g == nil {
 		log.Printf("Game '%s' non-existant; making it now", requested_game_name)
 		var err error
@@ -76,7 +76,7 @@ func (c *Controller) StartGame(w http.ResponseWriter, req *http.Request) {
 			return
 		}
 		go g.run()
-		c.Games.add(g)
+		c.Games.Add(g)
 	} else {
 		log.Printf("Game '%s' already exists: %p", requested_game_name, g)
 		b, _ := json.Marshal(NewFailure("game already exists"))
@@ -254,6 +254,7 @@ func (c *Controller) getGameId(path string) (string, error) {
 	return key, err
 }
 
+// MapLock is simply a map and a RWMutex
 type MapLock struct {
 	M map[string]*Game
 	sync.RWMutex
@@ -262,14 +263,15 @@ type MapLock struct {
 // get is a function that returns a game if found, and creates one if
 // not found and force is true. In order to get a hash (rather than use
 // the string you pass) send "" for id.
-func (ml *MapLock) get(id string) *Game {
+func (ml *MapLock) Get(id string) *Game {
 	ml.Lock()
 	g, _ := ml.M[id]
 	ml.Unlock()
 	return g
 }
 
-func (ml *MapLock) add(g *Game) {
+// add is used to insert a new game into this MapLock
+func (ml *MapLock) Add(g *Game) {
 	ml.Lock()
 	ml.M[g.id] = g
 	ml.Unlock()