Added stop method to AccountManager

Ignore-this: acc835ea04f0910f756427e35a2c1829

darcs-hash:20090325193053-1e3d8-05cd7b2f146673814317ad602232ae91d1fdd8f9
Fixed loading of SettingsObject in case of backwards-incompatible changes

Ignore-this: 3afd884a720ba82940cb0f5c4326ba0c

darcs-hash:20090325193119-1e3d8-d8d571afbb6e2c31a3c1760cde58c8abf01733a8