added a sequence combinator
Restore previous process1.take implementation
Add test for pipeW and stripO
Merge branch 'append4-final' of https://github.com/etorreborre/scalaz-stream into etorreborre-append4-final

Conflicts:
	src/test/scala/scalaz/stream/ProcessSpec.scala
Merge branch 'etorreborre-append4-final' into append4-final
Readd lost prefixSums alias
renamed zipPrevious to zipWithPrevious
Merge branch 'append4-final' of github.com:scalaz/scalaz-stream into append4-final