Merge branch 'kvo-dealloc-race' into fix-kvo-capturing-self

Conflicts:
	ReactiveCocoaFramework/ReactiveCocoa/NSObject+RACPropertySubscribing.m
	ReactiveCocoaFramework/ReactiveCocoa/RACSignal+Operations.m
Remove `observer` parameter from all KVO APIs

Fixes #472.
Merge branch '3.0-development' into fix-kvo-capturing-self

Conflicts:
	ReactiveCocoaFramework/ReactiveCocoa/NSObject+RACPropertySubscribing.m
Merge branch '3.0-development' into fix-kvo-capturing-self
Warn about new RACObserve behavior

Only when WE_PROMISE_TO_MIGRATE_TO_REACTIVECOCOA_3_0 is defined,
and when observing something other than `self`.
Clarify warning behavior, use plain token pasting
Restore deprecated RACKVOWrapper method
Restore deprecated RACPropertySubscribing method
Merge branch '3.0-development' into fix-kvo-capturing-self
Stub new CHANGELOG section
CHANGELOG
Change updated examples into "to update" section
Merge remote-tracking branch 'origin/3.0-development' into fix-kvo-capturing-self
s/id/instancetype
Fix disposable usage errors in RACKVOWrapper
Merge pull request #1034 from ReactiveCocoa/fix-kvo-capturing-self

BREAKING: Stop tying KVO observation lifetime to self