ref/cmd/principal: Add more blessing information getters.
This closes veyron/release-issues#991.
This change add the following commands to make driling into
blessings more command line friendly:
(1) 'principal get publickey' gets the publickey of the principal.
(2) 'principal get default' and 'principal get forpeer <peer>'
now take the following flags.
(a) 'principal get default --names' prints the names of the blessings.
(b) 'principal get default --rootkey <chainname> prints the root key of
one of the names from (a).
(c) 'principal get default --caveats <chainname> prints the caveats of
one fo the names from (a).
Change-Id: I00754e2dd047748931c9be504033118e3171ca68
3 files changed
