Fix building on ghc-7.6 (base 4.6) for #713

Just add missing functions or rewrite in simple cases.
Also add explicit base version requirement.
Merge pull request #718 from dylex/ghc7.6

Fix building on ghc-7.6 (base 4.6) for #713
Simplify indentation rules for guards
Indentation example
Merge pull request #719 from purescript/pipe

Simplify indentation rules for guards
Bump version
Fix #694, take 2
Merge pull request #722 from purescript/694-take-2

Disallow partially-applied nested type synonyms in types
Add span information to errors
Merge pull request #723 from purescript/432

Add span information to errors
Fix #725
Merge pull request #726 from purescript/725

Fix #725
v0.6.1.2
Catch erroneous (singleton) recursive definitions

We can't safely bypass the extra immediate reference check even when
only one definition is involved in the recursion.
Merge pull request #728 from dylex/master

Catch erroneous (singleton) recursive definitions
Revert "Catch erroneous (singleton) recursive definitions"

This reverts commit 2bd5dc46fa95bff3812f4d4e089617a53fefb186.
Remove STArray implementation.
Do not descend into Let bindings multiple times during desugaring
Add back @dylex's binding groups change.
Make everywhereOnValuesM only apply functions once at top level

The traversal functions already pass their results through the
functions.  There should be no need to do it again.