MANTA-2081 update node-manta for access control and subusers
MANTA-2284 mchmod =<foo> removes all tags from a resource
MANTA-2289 mchmod +-foo replaces all tags
make mchmod +/- failures clearer
mchmod look at the correct error
support old client.user usage
add support for user-generated presigned URLs
Merge branch 'access-control'

Conflicts:
	lib/client.js