Merge pull request #51 from xhaakon/master

Fix PUOID storage and related stuff

The puoid persistence logic was broken by the sd card support and this PR fixes it
[tests] wait until storages are ready

We have to wait until the storages are initialized before proceeding
with the test case execution.
[tests] fix MTPResponder_test::testSetObjectReferences()

On devices with many stored files, 1000 might be a too low object handle
to be invalid.