updated tests to new specta style
added a failing test
keep object around unsafeily
dispose of the trigger subscription once we get a value
Test that the target is deallocated when it is a subclass of a subclass in RACKVOWrapperSpec
Combine stops KVO on target deallocation tests
don't need to be blocks anymore
Merge pull request #283 from github/fix-tests

Updated tests to new specta style
Merge pull request #284 from github/fix-notification-cycle

Fix notification cycle
Merge branch 'master' into take-until-dispose
use a compound disposable
more tests for property subscribing
Merge pull request #286 from github/take-until-dispose

Fix -takeUntil: disposal
refactor the KVO wrapper to fit better with KVO signals
more tests
lazy KVO signal
document the block type
array instead of a set
varargs
slightly more documentation