Add failing test from #723
Copy the input argument to +merge:

If it's an NSEnumerator, it'll become exhausted after the first
enumeration, invaliding future subscriptions.
Merge pull request #724 from ReactiveCocoa/merge-fast-enumeration-bug

Copy <NSFastEnumeration> argument to +merge:
Merge remote-tracking branch 'origin/master' into 2.0-development
Revert "Merge pull request #709 from ReactiveCocoa/add-fishhook"

This reverts commit 5043e26d317f992445446d26c78729f5ea2ad422, reversing
changes made to f548b20f5e3f8c540d303ade7256afb0fd4b8208.

Conflicts:
	ReactiveCocoaFramework/ReactiveCocoa.xcodeproj/project.pbxproj
Merge pull request #729 from ReactiveCocoa/remove-fishhook

Remove fishhook, disabling automatic iOS backtraces
Merge branch '2.0-development' into uikit-bindings
Moved all NSTextField tests to RACViewChannelExamples.
Removed unused headers.
Changed RACChannelViewExamples to use numeric properties instead of string properties.
Why do the strongify macros silence the non-void return function exits without a return warning anyway.
Add RACViewChannelExamples to UIControlRACSupportSpec.
Fix the RACViewChannelExampleSetViewValueBlock.