Remove Complete state lock

Use `will` so that the tests can timeout rather than deadlock
Improve documentation around the `hasConnected` variable
Merge branch 'multicast-connect-race' of github.com:ReactiveCocoa/ReactiveCocoa into multicast-connect-race-test

Conflicts:
	ReactiveCocoaFramework/ReactiveCocoaTests/RACMulticastConnectionSpec.m