Fixed new warnings as errors

Oops, I plead guilty ; closes #70
Added test for bug #66 (GADTs)
Thanks for the report
Updated vim script, contributed by Jonathan Derque

Thanks a lot !
ref: issue #54
a few more ocp-indent tests for combination cases
Allow ocp-indent-region to be called interactively.
A huge, weird string test that passes.
Added a test case for a module definition with a type replacement on the signature.
fixed broken js-type tests (two tests had syntax errors)
a test for a minor tweak to function indentation from yminsky
Jane Street tests for module-level comments after all declarations
Jane Street tests for more complex record syntax: with combined with module scope
Fixed #66 ('type' keyword for gadts)
Thanks @jonathanderque for finding the bug _and_ the fix :)
Fixed indent of comments at the end of modules
if after a newline, don't indent like the last expr
resolved conflicts from merge with OCamlPro/ocp-indent master