Add more integration tests for Regress
Add a task to TODO.rdoc
Automatically convert array elements to GValue
Remove obsolete notes
Refactor tests for ISignalInfo
Refactor unit tests for GirFFI::Builder

- Move tests to dependencies
- Remove outdates tests
- Start re-organizing tests by method
Remove TODO note

We'll tackle this problem if and when it occurs.
Move GObject::ValueArray test to integration tests
Remove odd tests
Remove a TODO

A length check is not needed, since the array's actual length is always
used.
Merge outgoing conversion check methods
Remove ReturnValueBuilder#has_conversion?
Deprecate ModuleBase#load_class in favor of #setup_class
Add test for Regress.test_struct_a_parse
Extract TypeBase#gir_ffi_builder
Move ClassBase.gir_info to TypeBase
Generate classes for callbacks
Set up constants in created callback classes
Make #full_type_name available for ICallbackInfo
Use new callback classes in generated function definitions