Fix the most prominent crash reports from ABB 1.4.0

[mario]

Environment

Adblock Browser 1.4.0
Any iOS version
Any device

Background

After releasing ABB 1.4.0 we've accumulated a list of stack traces of the most prominent crash reports.

Want to fix

Fix all bugs indicated by the following stack traces:

• Stack Trace for function signature specialization <Arg[ 0] = Owned To Guaranteed> of KittCore... (63 crashes*)
• Stack Trace for function signature specialization <Arg[ 0] = Owned To Guaranteed, Arg[ 1] = Owned... (56 crashes*)
• Stack Trace for - [WebRequestEventDispatcher onHeadersReceived:withDetails:responseBlock:] (24 crashes*)
• Stack Trace for - [ConnectionAuthenticator authenticateChallenge:resultHandler:] (18 crashes*)
• Stack Trace for function signature specialization <Arg[ 0] = Owned To Guaranteed> of KittCore... (16 crashes*)
• Stack Trace for - [WebRequestEventDispatcher onHeadersReceived:withDetails:responseBlock:] (16 crashes*)
• Stack Trace for - [ConnectionAuthenticator authenticateChallenge:resultHandler:] (15 crashes*)
• Stack Trace for - [WebRequestEventDispatcher onHeadersReceived:withDetails:responseBlock:] (11 crashes*)
• Stack Trace for generic specialization <KittCore.ChromeTab> of Swift._ArrayBuffer._getElementSlowPath... (8 crashes*)
• Stack Trace for function signature specialization <Arg[ 0] = Owned To Guaranteed, Arg[ 1] = Owned To... (5 crashes*)

*as of 2016-07-05, 3 p.m.

Remark for testers

Please note that we only know the sources of the described crashes, as we can only rely on stack traces provided by the crash reports. We do not know how the crashes can be manually triggered and thus there's no way to reliably reproduce them.
The only way to verify that those bugs are fixed, is by monitoring the crash reports for upcoming development builds/release builds and compare them to the attached stack traces.

[mario]

Duplicate of #4216, #4219, #4220, #4222