bootstrapper doesn't use assertion statements anymore to assure it is pyo compatible.

Fixed terrible bug which would cause include paths not to be resolved anymore.
Fixed major bug that would cause variable inheritance to fail.

Added new per-directory symlink simulator, to make configuration on windows much easier.
Improved error messages to tell everything you need to know right away.
Made sure that native paths are coming from the KVStore, at least when pathlists are involved.

It would be easy to use native paths everywhere, and maybe that's going to be the next edit.
In the same time, the environment-variables key was made into environment.variables to be similar
to the one in the package schema.

fixes #20
Merge branch 'issues/20'