Conflict with NoSquint 2.1.9

[streetwolf]

NoSquint has an option called 'Global Settings'. With Private Tabs enabled the 'Global Settings' menu is not fully displayed. Only the OK, Cancel, and Help buttons are shown. Can you have a look into this?

NoSquint: Firefox Extension - https://urandom.ca/nosquint/

Someone else filed a bug report about this problem over at NoSquint:

Private Tab 0.1.1 breaks NoSquint Options · Issue #80 · jtackaberry/nosquint - jtackaberry/nosquint#80

[Infocatcher]

Seems like
https://github.com/jtackaberry/nosquint/blob/2.1.9/src/content/prefs.js#L15

this.isPrivate = isWindowPrivate();

is called too early (may also cause jtackaberry/nosquint#73).
And Private Tab overrides PrivateBrowsingUtils.isWindowPrivate() and checks window.document.documentElement:
https://github.com/Infocatcher/Private_Tab/blob/0.1.2/bootstrap.js#L2161
=> https://github.com/Infocatcher/Private_Tab/blob/0.1.2/bootstrap.js#L272

And strange things happens, if window.document.readyState == "uninitialized".

[Infocatcher]

Looks fixed for me after d6ead0d commit.

Test version: private_tab-0.1.3pre3-fx-sm.xpi (source)