Mark BB10 IndexedDB support as partial

BB10 has an outdated IndexedDB implementation following the spec from April 2011 (http://www.w3.org/TR/2011/WD-IndexedDB-20110419/).

As the current spec differs in regards of transaction types and versioning, and code working with up-to-date implementations doesn't work on BB10, it would be cool to have BB10 support marked as partial. Even if it's just a heads-up for developers that their code might not work on a BB10.

As reference, see this example code from RIM: https://github.com/grahamzibar/Folio/blob/master/folio/db/Indexed.js