2.2, InfoProvider: Fix NPE

GetSpaceTokensMessage and LinkgroupDetailsMsgHandler may return null for
uninitialized fields. This causes NPEs in the respective handlers.
This patch ensures that the messages return initialized values (i.e.,
empty sets) instead of null.

Ticket: http://rt.dcache.org/Ticket/Display.html?id=8350
Acked-by:
Target: 2.2
Require-book: no
Require-notes: no
Fix ArrayIndexOutOfBoundsException when processing
multiple surls invoking srmget.

        Ticket: #8083
        Acked-by: Christian Bernardt <christian.bernardt@desy.de>
        Target: trunk
        Request: 2.9
        Request: 2.8
        Request: 2.7
        Request: 2.6
	Request: 2.2
        Require-book: no
        Require-notes: yes

    RELEASE NOTES

Fix ArrayIndexOutOfBoundsException when processing
multiple surls invoking srmget. Addresses RT #8083
(cherry picked from commit e73977e85d6708cdf0aa23268ef1113c738f3b09)

Conflicts:
	modules/srm-client/src/main/java/gov/fnal/srm/util/SRMGetClientV2.java
Merge pull request #655 from DmitryLitvintsev/fix/2.2/8083

Fix/2.2/8083
Merge pull request #658 from kschwank/fixInfoProviderNPE/2.2

Fix info provider npe/2.2
Preparing for release of 2.2.26
bumping number for next release cycle
srmclient: Fix export SRM_PATH in srmrmdir
Merge pull request #666 from chrber/fix/srmrmdirExport

srmclient: Fix export SRM_PATH in srmrmdir
Suppress nfs' file protocol from being published

The dcache-info-provider publishes all doors as endpoints by default. A
couple of doors are already configured to be excluded from this, but the
nfs door isn't and causes an file://xyz/ endpoint to be published.

Ticket: 8365
Acked-by:
Target: master
Request: 2.9
Request: 2.6
Request: 2.2
Require-book: no
Require-notes: yes