Update htdocs/webcam.js

New function called  freezy_silently.

I've created this function because I need to hide the flash, but if you are using the shutter sound, calling freezy will play and I really don't want it.
I just don't want to disable sound, freeze and re-enable the shutter passing my sound path again, so I can say this a shortcut :)

Hope it help others...
By the way, I didn't change the minified source.