Updated libextobjc to get new configurations.
Merge pull request #402 from ReactiveCocoa/bump-libextobjc

Updated libextobjc to get new configurations.
allow custom names for schedules
4 debug eyes only
Merge pull request #409 from ReactiveCocoa/named-scheduler

Custom named scheduler
fix a cycle created by -startWith:
Merge pull request #416 from ReactiveCocoa/fix-cycle

Fix text signal cycle