Remove QueryStringFilter requires from Protocol/HTTP

[probins]

see #147

No logic changes; only affects builds

[elemoine]

I'm +1 with this change. But I'd like to have @tschaub's opinion, since he's the one who said the dependency should be removed in 3.0.

[tschaub]

I added that comment so behavior would remain unchanged for people using this functionality. I'm ok with the change assuming there is an accompanying comment in the release notes. I do think there is some caution warranted here - we risk making it extremely hard to get a proper build by having all this optional functionality (and only having it documented in the release notes).

[elemoine]

@tschaub, I agree. Maybe we should merge this one and stop making such changes for 2.12. We may also want to have a "script dependency changes" section in the release notes, where we explain clearly how build profiles need to be changed.

The current master already includes lots of changes compared to 2.11, with some of them somewhat disruptive for users (e.g. deprecated.js, the script dependency changes). We may want to stop and think about releasing 2.12.