Tests for lastOr and stripNone
Double the performance of lastOr
Added consume() and consumeOne() to writerTopic.
Do not require an immutable.IndexedSeq

An immutable IndexedSeq for the split function of process1.repartition is a too
specific requirement. Allowing also mutable.IndexedSeq has the advantage that
(s: String) => s.split(x) (i.e functions that split into arrays) are valid
parameters.
Merge pull request #112 from fthomas/process1-tests

Tests for lastOr and stripNone
Add process1.(maximum|minimum)(|By|Of)

This adds the following on process1:
 - maximum
 - maximumBy
 - maximumOf
 - minimum
 - minimumBy
 - minimumOf

These emit a single value if their input is non-empty, and no value if it is
empty. They are similar to the functions on scalaz.Foldable:
https://github.com/scalaz/scalaz/blob/scalaz-seven/core/src/main/scala/scalaz/Foldable.scala
Align maximumBy with scalaz.Foldable.maximumBy

before:
  Process("ab", "cd", "ef").maximumBy(_.length) == Process("ab")

after:
  Process("ab", "cd", "ef").maximumBy(_.length) == Process("ef")
Use the Sink type alias
Remove unused java.io.File import.
Fix typo: Bytes -> Byte
Merge pull request #123 from fthomas/docfix

Use the Sink type alias in io
Merge pull request #116 from fthomas/maxmin

Add process1.(maximum|minimum)(|By|Of)
Merge pull request #113 from fthomas/repartition

Do not require an immutable.IndexedSeq for process1.repartition
Merge branch 'master' into utf8Decode

Conflicts:
	src/test/scala/scalaz/stream/ProcessSpec.scala