Demote/remove development time logging
Do not use quote chars in dbus owner identification string

Makes it a tiny bit more compact. And since the string length is limited,
we might end up cutting of the final quote char anyway.
Fix memory leak in mce_dbus_ident_delete()
Remove name owner information before cleaning up dbus connection

The name owner tracking uses dbus handlers, and those must be removed
before generic handler cleanup or connection closing.
Fix memory leak in gconf_value_set_from_string()
Add atexit handler for builtin-gconf module

Releasing the default_client data makes it easier to detect possible
memory leaks.