cleaner: Fix null pointer exception in 'hsms attached to pool' command

Addresses a null pointer exception in the cleaner.

Ticket: http://rt.dcache.org/Ticket/Display.html?id=7769
Target: trunk
Request: 2.6
Request: 2.2
Require-notes: yes
Require-book: no
Acked-by: Paul Millar <paul.millar@desy.de>
Patch: http://rb.dcache.org/r/5493/
gplazma2-jaas: add principal mutator plugin

JAAS plug in can be configured to use any jaas login module. As a
result we may get principas which can't be handles by gplazma. New
MutatorPlugin allows to convert some principals to supported equivalents.

in gplazma.conf:
auth jaas
...
map optional mutator gplazma.mutator.accept=org.apache.activemq.jaas.UserPrincipal gplazma.mutator.produce=username
map sufficient nsswitch
...

The supported output types:
   dn
   name
   username
   kerberos
   fqan

Ticket: #7763
Acked-by: Paul Millar
Target: trunk, 2.6, 2.2
Require-book: yes
Require-notes: yes
Signed-off-by: Tigran Mkrtchyan <tigran.mkrtchyan@desy.de>
Merge pull request #11 from gbehrmann/fix/2.2/rb5493

cleaner: Fix null pointer exception in 'hsms attached to pool' command
all: Avoid error when hostkey is not readable to user

The dcache script checks the format of the hostkey whenever it is invoked.
Since read-access to the hostkey should be restricted, the dcache script will
generate an error whenever the script is invoked by somebody without
read-access to the hostkey.

This patch resolves the problem.

(there is a related question about whether the check should be run for
commands like 'dcache status', but we can discuss that another day)

Release notes: In a section about the dcache script, describe that we
fixed a bug that caused 'grep: /etc/grid-security/hostkey.pem: Permission
denied' to be printed.

Target: trunk
Request: 2.2
Acked-by: Paul Millar <paul.millar@desy.de>
Patch: http://rb.dcache.org/r/4476/
Merge pull request #12 from gbehrmann/fix/2.2/fix_unreadable_hostkey

all: Avoid error when hostkey is not readable to user