Update test cases so that they parse with GHC.
Unfail exact printing of brackets.
Add TySplice. Fixes #113 and #139.
Add test case for #113.
Add test case for now fixed #139.
Preserve spaces when pretty-printing OPTIONS pragmas. Fixes #140.
Improve error location when record wildcards are turned off. Fixes #10.
Add  testcase for #10.
Restructure Context/Asst to replicate source structure.

Makes a number of existing test-cases round-trip. AST  suggested by @niklasbroberg in #17.
Parse parenthesized equality constraints. Fixes #17.
Add test case for #17.
Admit bracketed instance heads. Improves #7.
Add test case for #7.
Add test case for now fixed #36.
Add test case for now fixed #117.
Add test case for now fixed #115.
Parse "Constraint" as a kind with ConstraintKinds enabled.
Add a test case for ":: Constraint" kinds.
Improve exact printing of (->).

The actual work consists of putting the right annotations in the AST so we can distinguish '(' thing ')' from just thing.
Add a test case for exact printing of (->).