Log Message:
Update to 1.17.0

CHANGELOG:
1.16.0.1 --> 1.17.0
===================

AST changes:

* Replaced VarA with AppA in Asst (#168).
* Promoted list/tuple members changed from Promoted to Type (#162).
* Update PatBind, Match, and Alt from containing Binds to Maybe Binds to
  distinguish between empty where clauses and where clauses with no
  binds (#244).
* Add RoleAnnotDecl and Role to support Role annotations (#215).
* Move NameSpace field from EVar/IVar to EAbs/IAbs.

Other changes:

* Add standalone parsers for ImportDecl.
* Fix pretty-printer bugs for HaRP (#160).
* Insert parentheses when pretty-printing non-atomic bang types (#169).
* Un-reverse confusion of left and right arrow (#175).
* Prettyprint option pragmas like 1.15 (#172).
* Conditionally insert lines when pretty-printing declarations (#171).
* Distinguish deriving (Show) from deriving Show (#189).
* Allow parsing of unicode subscript and superscript functions (#173).
* Pretty print unboxed tuples with spaces (#193).
* Improve performance when parsing long extension lists (#200).
* Properly pretty print constructor and class operators (#204).
* Read Haskell source files as UTF-8 (#223).
* Fix ExplicitNamespaces parsing (#216).
* PolyKinds implies KindSignatures (#220).
* Preserve location information for infix binds (#205).
* Preserve positional information in checkPattern (#231).
* Maintain correct line numbers when parsing multiline GHC_OPTIONS (#218).
* Correctly parse "*" with TypeOperators (#81).
* Export the "pretty" method (#222).
* Add javascript calling convention for foreign imports (#236).
* Add non-greedy parsers for module heads (#191).
* Add a flag to disable arity checking when parsing (#260).
* Parse "-" in type signatures (#206).
* Add support for type wildcards and expression holes (#252).
* Add support for Pattern Synonyms (#197).
* Bump the happy lower bound (#250).
* Make test suite pass on GHC 7.12 (#224).
* Support linking Haddock comments to AST nodes (#213).
* Parse multiline LANGUAGE pragmas (#217).
* Parse trailing where (#25).
* Parse modules starting with pragmas and indented
  "module" keyword (#122).
* Use pretty-show to get human readable test outputs.
* Respect fixity declarations inside where/let/class in
  `applyFixities` (#212).
* Correctly parse the combination of view patterns and bang patterns. (#276)