Add type/value aliases for scalaz.\/ and co.

Add type/value aliases for:
* Disjunction  <=> \/
* DLeft        <=> -\/
* DRight       <=> \/-
* DisjunctionT <=> EitherT
add an EndoUsage
Add Foldable1.toNel
Implement Foldable1.toNel with foldMapRight1

Per @S11001001's recommendation (I think), as this will avoid expensive
`NonEmptyList` appends.
Merge pull request #824 from ceedubs/foldable1-toNel

Add Foldable1.toNel
Fix typo

thanks @jcoveney for catching it. Obviously @ceedubs is slacking.
Merge pull request #820 from stew/EndoUsage

add an EndoUsage
Merge pull request #805 from adelbertc/either2disjunction

Add type/value aliases for scalaz.\/ and co.
optimize Dequeue
Scala 2.11.3
suppress warning