As part of our teamwork up to the 1.0 release, we are refactoring newtmgr. One
of the pieces of this work was to get newtmgr to use cbor instead of json for
encoding. This allows several things
1. more efficient encoding of hash values. Previoulsly these were base-64
encoded. Now they are encoded in cbor as byte stringds
2. More efficient upload and download of files/cores etc.
These changes have been checked in.
YOU WILL need to upgrade newtmgr and mynewt-core at the same time to get these
changes. Otherwise you will receive errors when running newtmgr commands.