Lift with a signal of tuples of arguments.
Add Producer.try and Producer.tryMap
Merge pull request #1398 from ReactiveCocoa/lift-with-signal-of-arguments

Lift with a signal of tuples of arguments.
Referencing the right class in the RACScheduler method deprecation message.
Merge pull request #1401 from JaviSoto/patch-1

Referencing the right class in the RACScheduler method deprecation message
The Return to Compilability

Updated for Xcode 6 beta 3.
Get rid of some uses of Box
Signal.{takeWhile,filter} should return optionals

Then, no initialValue is required. If you want a non-optional signal,
simply chain through ignoreNil.
ignoreNil -> unwrapOptionals, add forced variant
Refactor Signal to always require an initial value

Don’t allow a backdoor in the constructor itself.
`forceUnwrapOptionals` can be used instead, for cases where you _really
know_ that there will be an initial value, and just can’t easily prove
it.
Refactor Producer as a struct

Also rename BufferedProducer to EventBuffer, and have it _return_ a
Producer instead, since the type can’t be derived from anymore.
Refactor Signal into a final class—compose!

Inheritance sucks.
Merge remote-tracking branch 'origin/master' into swift-development
Get rid of Objective-C tests

They won’t be maintained, after all.
++Quick for Xcode 6 beta 3 support
Clean up memory management in Signal

Except for Signal.buffer, which is currently pretty #dangerzone.
Add pipeWithInitialValue for controllable Signals
Retain a promise's action until it's been resolved
Parameterize ScopedDisposable by innerDisposable

Since it layers memory management semantics on top of the inner
disposable, it’s important to be able to access the inner one without
holding on to a separate reference to it.
Stop observing notifications when Signal deallocs