complete the signal and errors
moved -dealloc into the Lifecycle section
added tests
Merge pull request #375 from ReactiveCocoa/complete-command

Complete command signals on dealloc
Send complete on dealloc a RACEventTrampoline
Merge pull request #379 from kkazuo/complete-on-dealloc

Send complete on dealloc a RACEventTrampoline
Documentation
Style fixes
Remove unnecessary test (actually testing -takeUntil:)
Merge branch 'did-dealloc-signal' (pull request #376)