[FF] Session Manager in X-notifier

X-notifier has separate session manager in it to access accounts in background.

* When you disable 'Multiple login',
If you click account in XN, XN copy cookies to browser.

* When you enable 'Multiple login',
If you click default account in XN, XN copy cookies to browser.
If you click non-default account, XN make browser to use XN's session manager.
This will be displayed as a 'underline' in tab title.

You can change which session to use in tab menu(right click tab title).
'None' means not to use XN's session manager.

When you see wrong accounts while you use mails
If you enable 'Multiple login', browser uses XN's session manager.
When you open a link to new tab, the tab does not use XN's session manager by default.
That's why you logged in with default account .
To prevent this, enable 'Keep session for links' in Options.