Anamorphism

This is a alpha version of RxSwift 2.0.

• Renames ImmediateScheduler protocol to ImmediateSchedulerType
• Renames Scheduler protocol to SchedulerType
• Adds CurrentThreadScheduler
• Adds generate operator
• Cleanup of dead observer code.
• Removes SpinLocks in disposables in favor of more performant OSAtomicCompareAndSwap32.
• Adds buffer operator (version with time and count).
• Adds range operator.
• Adds repeat operator.

Check out Migration guide to RxSwift 2.0