uBlock's `third-party` filter option does not follow strictly ABP's semantic

[gorhill]

Exposed by #109.

It appears that officially, in ABP, third-party means "third-party according to document in current frame", while in uBlock it is interpreted as "third-party according to document in current tab".

Also, for ABP, a plug-in is a distinct document within its own frame. For example, requests to fwmrm.net, from within a plug-in pulled from fwmrm.net, embedded in example.com is interpreted as first-party by ABP (third-party by uBlock).

[gorhill]

Ok I have the code in, commented out, until we can find an instance of a plug-in which works in ABP but not in uBlock.

[gorhill]

Will wait for a case.

[gorhill]

Fixed with 4fce81e.