XML format
----------
- Document the format
- Write a scanner to create XML from annotated headers
- Add attributes to connect signals to their default handlers
  and wrappers to their vfuncs
- Add a way to specify default values
- Add a way to specify annotations
- Add a way to mark init functions like gtk_init

Binary format
-------------
- Sort arrays so that we can use bsearch for lookup
- Maybe add hashes to lookup interfaces and functions in interfaces
- Add default values
- Make annotations more flexible (and typed)

Compiler
--------
- Cleanup, maybe turn the nodes in to objects to avoid the horrific 
  type switches
- Add thorough error checking

Repository
----------
- Reconsider the current clunky API, maybe an iterator approach is better
- Add thorough error checking
- Use hashes 
- Maybe allow populating repositories at runtime
- Think about a system-wide repository mapping namespace ids to 
  libraries/metadata files
- Fix extra indirection for out parameters in invoke

General
-------
- More tests
- Check how the format scales to something the size of GTK+