[LMP Potorchu] Cache the window ID for the visual widget.

Seems like GStreamer can request the ID from another thread (especially in
case with probes).
[Azoth] Added icon for iSida bot v. 4.
[Azoth Xoox] Added caps for "http://v4.isida-bot.com"
[Azoth Xoox] Proper icon for previous iSida 4 caps.

Hey, guys, stop changing caps please!