Fix logic errors in handleWith and mapFailure

this may refer to a computation before it was executed and would lead to bizarre errors where a previously computed error appears to not have been computed yet
Merge pull request #1 from jedesah/topic/remove_this_handleWith

Fix logic errors in handleWith and mapFailure
Merge branch 'master' of github.com:whitepages/validation-future

Conflicts:
	src/main/scala/com/whitepages/ComplexTask.scala