Code paths

[tsloughter]

A test and feature we need to add is around not having plugins and their deps in the code path when compiling.

We can test this with multiple versions of a test app used as dep and dep of a plugin included but that is missing an include in the plugin version that exists in the version expected by the app we are building.

[tsloughter]

This is covered in the plugins test checkbox in on the tests checklist #45