* Fix a resource leak in LdLibrary.
* Add missing property change notifiers
to ld_diagram_object_{get,set}_storage().
* Don't unref the parameter in ld_symbol_category_remove_{symbol,subcategory}
if it wasn't actually removed from the internal list.
* Fix a cyclic dependency problem in LdDiagram.
This is required for gtkdoc-scangobj. So far it's much like it's been
before, the main differences are that source files are in two directories
from now on and the build process has two stages.
