Adapt the doc of sum to its implementation
Change sum to always emit one element and add prefixSums
https://github.com/scalaz/scalaz-stream/issues/132 https://github.com/scalaz/scalaz-stream/issues/132 unsafeChunkR doesn't actually reuse the same buffer.
minor efficiency change, do the length test first (and use `array.length` rather than `.size`)
Replace id[A].map(f) with lift(f)
Merge pull request #158 from jedws/master

unsafeChunkR doesn't actually reuse the same buffer.
Merge pull request #162 from fthomas/use-lift

Replace id[A].map(f) with lift(f)
Fix continuous signal so it always returns newest value
Add process1.zipWithIndex and zipWithState
Allow the state update to depend on input elements
Merge pull request #163 from radekm/scalaz-fix-signal-continuous

Fix continuous signal so it always returns newest value
Merge pull request #164 from fthomas/zipWithIndex

Add process1.zipWithIndex and zipWithState
Merge branch 'docfix2' of https://github.com/fthomas/scalaz-stream into fthomas-docfix2

Conflicts:
	src/test/scala/scalaz/stream/ProcessSpec.scala
Merge remote-tracking branch 'origin/master'
Removed use of lazy vals in append/fby/onComplete
Added tests for expected failures
updated readme