Strings cannot contain non-UTF8 bytes, this is ensured in JSON
marshaling/unmarshaling. At the same time using human-readable strings
can be rather restrictive, because we have 64-byte key limit.
Signed-off-by: Evgenii Stratonikov <e.stratonikov@yadro.com>
Autorization can be dedicated to a separate contract, iterating over
multiple keys can be costly. Also add committee as "default" admin:
everything is allowed for it.
Signed-off-by: Evgenii Stratonikov <e.stratonikov@yadro.com>