stretch: query info about hostnames

[gabrc52]

for instance this query gets details about matrix: get_host MATRIX.MIT.EDU *

or for instance to get what an alias points to:

rgabriel@thinkpad:~$ qy get_hostalias
alias:              EC.MIT.EDU
canonical_hostname: *

alias:              EC.MIT.EDU
canonical_hostname: SCRIPTS-VHOSTS.MIT.EDU

to get all the hostnames you control (subset of get_ace_use):

rgabriel@thinkpad:~$ qy get_host_by_owner
ace_type: RUSER
ace_name: rgabriel

name: EC-SERVER-MGMT.MIT.EDU

name: DORMDIGEST.MIT.EDU

name: PETROCK.MIT.EDU

name: MATRIX.MIT.EDU