- Make it possible to use :mod:`zope.component`
- Provide a concise list of all the available APIs in that module and
  link them to their in-depth descriptions.
- Fix several xref errors
- Add documentation for setHooks/resetHooks.

This also makes it possible to get useful help at the REPL or command
line:

$ python -c 'import zope.component; help(zope.component.getAdapters)'
Help on function getAdapters in module zope.component._api:

getAdapters(objects, provided, context=None)
    Look for all matching adapters to a provided interface for
    objects

    Return a list of adapters that match. If an adapter is named,
    only the most specific adapter of a given name is returned.

    .. seealso::
       Function `~zope.component.getAdapters` for notes, and
       `~zope.component.interfaces.IComponentArchitecture` for the defining interface.

And some internal links as well.

Remove mentions of 'IServiceService' from interface documentation, as that's not a thing.

Ensure resolution order is consistent.

- Use unittest runner directly (remove unneeded test_suite() methods). The same number of tests get run, but coverage will go down since the security-relevant tests just get skipped.
- Catch import errors due to inconsistent IROs and trigger test skips.

Fixes #45.

Tests won't be green until zope.configuration is released with its corresponding fix, as well as zope.security (which needs BTrees).