Make ArchivedFile load title regardless of how constructed.

If someone did $f = new ArchivedFile( null, 10 ); (ie load an
archived file based on id), $f->getTitle() would always return
false. We should populate the title when loading properties
from the db to prevent this. Having $f->getTitle() return
false only sometimes is sketchy.

Change-Id: Ia9d25d6b159aa45696c318d8c4a8ef0adffb3e47
Merge "Make ArchivedFile load title regardless of how constructed."