fix event prevention on chat restore

login_panel.html: remove useless quote character

index.rst: change duplicated `allow_muc` to `allow_otr`

Otherwise, we get errors "Cannot read property top of undefined".

The 0.8.2 release didn't include new builds due to an unnoticed build error.

Hebrew translation update

and one for logging out. Also added a favicon.

Elements in chat rooms are now hidden, instead of removed. Update tests to
reflect this.

Fixed problem with Strophe handlers zombies.
Remove zombie handlers for minimized chats (caused duplicate minimized chats).

* Make sure to rebroadcast presence when logging in after having just
logged out.
* Remove roster contacts when logging out, to avoid artifacts when logging in
with a different account.

Avoids username and pw inadvertently being added to the URL if the submit event
handler for some reason fails (which shouldn't happen of course).