TODO

MAJOR:

1. Support for PER encoding. Requires advanced subtype constraints support,
which is just completed.

2. Support for XER encoding.

3. Support for Information Object Classes.
   Status: support for parsing IOCs is mostly present. Support for slicing
   the IOCs to produce "views" is not yet designed.


MINOR:

1. Support for EXTERNAL, EMBEDDED-PDV and CHARACTER STRING types.