veyron/tools/principal: Various enhancements.
(1) Introduced the "create" command to initialize a principal with
a customized blessing (as opposed to forcing the "user@host-pid"
string that is automatically generated)
(2) Added a "bless" command to allow one principal to bless another
(3) Invoke AddToRoots in commands that add blessings to the store
(can be disabled with a flag)
(4) Do not require the VEYRON_CREDENTIALS environment variable
for commands like "help" and "dumpblessings", which don't need them.
(5) Update the test script
(6) Separate all store related commands to a sub-command
Change-Id: Ib94539464f90c14d91737717eadbf6d2112cef4c
2 files changed
