Replication encoding/encryption API now supports attachments.

During a pull, the _attachments objects for large attachments will have
a temporary "file" property that points to the local file path where
the attachment data can be found. The transformation block can read this
file, but must not modify it.
Removed all deprecated API methods.
Fixed incorrect values from CBLUnsavedRevision and CBLAttachment, for unsaved attachments

CBLUnsavedRevision:
-attachmentMetadataFor: and -attachmentNamed: would return nil for an unsaved attachment.
-attachments wouldn’t return any unsaved attachments.

CBLAttachment:
.length would return 0 for an unsaved attachment.
Optimizations for view indexing and querying

These shave a significant amount of time off of Ashvinder’s Test 12.
Merge branch 'master' of https://github.com/couchbase/couchbase-lite-ios