Bootstrap acceptance tests

[IljaN]

Ideas of what needs testing:

• migration of a user from OC A to OC B without mapping
• migration of a user from OC A to OC B with mapping
• migration of user shares through the different steps of remapping
• check that a locked user (during migration) only has read-only access over APIs (Webdav, OCS)
• migration of other metadata (to be expanded)
• after migration of two users U1 and U2 from OC A to OC B, check that data is still accessible and that the shares still point to the correct users (incoming and outgoing)
• after migration of just one user to OC B, check that the existing shares are pointing to OC A and still accessible

[IljaN]

The first idea which comes to mind is to have acceptance tests working across two instances. But there might be a simplification in that we use one instance but import under a different alias and re-export again.