Log Message:
Updated lang/ocaml to the newest version, 4.07.0.

This breaks quite a few dependencies, more commits to follow.

There are many bugfixes and improvements (see the Changes file), I will
summarise the changes that may cause breakage:

* all standard library modules are now packed into the Stdlib module;
* Unix.isatty now works under the native Windows ports
* strings and bytes are distinguishable in bytecode
* Module aliases are no longer removed in 'module type of' and
  'with module'
* soundness bugfix with non-generalised type variables and local modules
* Ident.t is now abstract and immutable
* only allow directives with filename and at the begining of the line