Twitch TV lacks a usable page title in the popout Video and popout Chat

this script generates a page title based on url and replaces the title

example:
on twitch.tv/nanopi/popout, the title will become "nanopi - Twitch Video"
on twitch.tv/nanopi/chat, the title will become "nanopi - Twitch Chat"

this improves navigation of Microsoft Windows taskbar (with and without Aero) and other window managers that display a grouped list of windows, especially when you popout chat/video windows on many twitch channels.