Add Parcelable interface to OwnCloudAccount and OwnCloudVersion

Parcelable interface is required to allow migration
of legacy code using raw platform Account passed
via Intent. To migrate those code paths, new User
model must be passed via Intent extras as well.

Since OwnCloudAccount and *Version are used (temporarily)
as implementation details of User, we need to make those
POJOs Parcelable as well.

Signed-off-by: Chris Narkiewicz <hello@ezaquarii.com>