Remove an item from the hash.
@param {String} key The key to remove.
@return {Boolean} True if the item was successfully removed.
function(key) {
        var me = this,
            value;

        if (me.containsKey(key)) {
            value = me.map[key];
            delete me.map[key];
            --me.length;
            if (me.hasListeners.remove) {
                me.fireEvent('remove', me, key, value);
            }
            return true;
        }
        return false;
    }