InsertionMap equality should be order independent.

The underlying structure stores an index that _can_
be used to pull keys back out in the insertion order,
but this index is not part of data and should not be
taken into account for equal / hashCode and alike.

This fits with the rest of the data structure, for
example map/flatMap occur in an arbitrary order.

This reverts a behaviour change introduced in
commit ec854db7180dbba78d19f6df6a0c040034f3245b
currying EphemeralStream#unfold for type inference
consistent file and class names for syntax.*Ops

* `ToXOps` and `XV` → `XOps` with file name `XSyntax.scala` or `XOps.scala`
  (latter if they don't contain `Syntax`)
* update Developer Guide
update `GenTypeClass`

* `Comonad` doesn't extend `Functor` directly
* take control over `IsEmpty`
* remove `ArrId`
* whitespace fixes
* move auxiliary functions into `////` blocks
Merge pull request #236
update package.scala scaladoc
add alias for comparing on Order
Merge branch 'scalaz-seven' of github.com:scalaz/scalaz into scalaz-seven
fix Heap#toUnsortedList.
Previous implementation is so slow. Because it returns sorted List in spite of toUnsortedList.
Merge pull request #238 from xuwei-k/package-scaladoc

update package.scala scaladoc
Merge pull request #239 from xuwei-k/Heap-toUnsortedList

fix Heap#toUnsortedList.