- This small header file contained a few unrelated typedefs.
Move those typedefs to the classes they relate to. This
**does** mean that some consumers need to #include something
else instead.
- Use type names more consistently.
Editorial: why are **pages** responsible for creating the jobs?
- Document meaning of error codes.
- The test-loader considers internal errors a real (test) failure,
while errors returned normally by the modules (e.g. because the
configuration is broken) to be ok for testing purposes.
Any job can be an emergency job; emergency modules spawn
emergency jobs (but conversely, a non-emergency module
can spawn an emergency job explicitly).
