
Installed paths: (read first)
    os.path.dirname(cdist.__file__)

    /conf/explorer
    /conf/type

User paths: (read after, overwrite)?

    $HOME/.cdist

    /explorer
    /type

    /manifest

    /cache

Additional paths:

    CDIST_EXPLORER_EXTRA_PATH=...
    CDIST_TYPE_EXTRA_PATH=...

    or

    -c dir -c dir2 -c ... => 
        add types and explorer from those directories
        last one wins?
            because they can only be appended to existing "$PATH"

Open questions:

    - How to tell types to use global explorer?
    - How to tell types to find other types?
