- documentation generation:
  - hush things up a bit, we don't need so much status info
    perhaps there should be an env var to enable these messages, or a
    "doc lint" tool.

- Glib::ParamSpec::param_spec: currently unimplemented, because it
  wants a GType derived from G_TYPE_PARAM_SPEC, but we don't provide
  GType <=> package mappings for that tree.  adding

- the ability to create new GSources in Perl could be handy, and wouldn't be
  hard to implement (a hash in place of GSourceFuncs).

- GEnum type for G_PRIORITY_VALUES?
- can't implement g_idle_remove_by_data because ... well, how would you
  search for the data value?
- proper cleanup for bad parameter types in Glib::Object::new?
  - would require either iterating over the list twice or cleaning up before
    the croak.  the latter is probably the way to go.
  - there is no way to clean up if gperl_sv_from_value() fails.
- GValue.xs may require the ability to register handlers for new fundamental
  types, since gperl_sv_from_value and gperl_value_from_sv croak on unknown
  or unimplemented data types.
  - gperl_value_from_sv should change to void return since it croaks on error.
    (can't do this without breaking ABI)
