Fix crash caused by WebSocket broadcasting error

Ignore error occurred when WebSocket client object is undefined.
Change packet access frequency graph position

Move the access frequency graph to the bottom and resize its height.
Add title and install new font

Show software name and WebSocket connection status on top of the page.
Install new font named 'Loto'.
Fix too many re-connection request bug

Fix too many reconnection request caused by multiple request from
WebSocket events.