Remove td_rev from CDTDocumentRevision

Make contrsuctors which take the needed TD_Revision attributes as params
and remove the TD_Rev property

Not wrapping TD_Revision within the CDTDocumentRevision class makes it easier
to work with revisions
Merge pull request #60 from cloudant/34405_remove_td_revision

34404 remove td revision from CDTDocumentRevision
Add NSPredicate query support to Cloudant Sync.
Clean up string literals and comments.
Put product type bundle back to com.apple.product-type.bunle for OSX Tests
Fix header documentation