vfsStream is now at 1.4.0

The vfsStream submodule linked to is two years old. Can you please update to the latest release.

[IvanChepurnyi]

This works fine if you install it via composer.

The git submodule was pointing to an old commit, so both cloning as well as installation via modman gave you the old 1.0.0 version. The above PR updates the commit.

[IvanChepurnyi]

I will just remove vfsStream as submodule, in favor of composer based installation.