xrootd, pinmanager, dcap, gplazma, admin, pool, poolmanager, pnfsmanager, webdav, cleaner: Add documentation and other minor property adjustments

Renamed xrootd.threads to xrootd.limits.threads.

Added time unit handling to MovePinRequestProcessor.

Renamed poolmanager.cache-hit-messages.enabled to
poolmanager.enable.cache-hit-message.

Renamed pinmanager.max-pin-duration to pinmanager.limits.pin-duration.

Renamed pool.cell.wait-for-files to pool.wait-for-files.

Target: trunk
Require-notes: yes
Require-book: yes
Acked-by: Paul Millar <paul.millar@desy.de>
Patch: http://rb.dcache.org/r/5855/
srm: Fix a few more property chaining errors

Target: trunk
Require-notes: no
Require-book: no
Acked-by: Karsten Schwank <karsten.schwank@desy.de>
Patch: http://rb.dcache.org/r/5858
dcap: Rename dcap.mover.overwrite to dcap.authz.mover-queue-overwrite and change to boolean property

We use true/false for all boolean properties and this property
should be no exception.

Target: trunk
Require-notes: yes
Require-book: yes
Acked-by: Tigran Mkrtchyan <tigran.mkrtchyan@desy.de>
Patch: http://rb.dcache.org/r/5865/
Add *.cell.export properties

Some services already support the cell.export property for declaring
whether a cell should be exported as well known. This patch adds this
property to all remaining services.

Most users will never touch this property, but it is useful for
non-standard expert deployments.

Target: trunk
Require-notes: yes
Require-book: yes
Acked-by: Karsten Schwank <karsten.schwank@desy.de>
Patch: http://rb.dcache.org/r/5866/
pool: Fix problems with restoring permanent migration jobs

Addresses a regression introduced in 2.6 in how migration jobs are
restored on pool startup. The issue was that restored migration jobs
would have "null" as the command string, which would show up in
migration ls and migration info output, as well as stored back to
the pool setup file when the save command was used. In the latter
case, a subsequent pool restart would fail.

Target: trunk
Request: 2.6
Require-notes: yes
Require-book: no
Fix regression in message queue length reporting

Addresses the issue that the message queue length in cells
is always reported as zero. This regression was introduced
between dCache 1.9.5 and 1.9.12.

Target: trunk
Request: 2.6
Request: 2.2
Require-notes: yes
Require-book: no
Acked-by: Albert Rossi <arossi@fnal.gov>
Patch: http://rb.dcache.org/r/5875/
Minor updates to third party libraries

Target: trunk
Require-notes: no
Require-book: no
Acked-by: Paul Millar <paul.millar@desy.de>
Patch: http://rb.dcache.org/r/5877/
srm: whitespace-only changes to Spring XML file
nfs: start LoginBrokerHandler only if NFSv4.1 is enabled

As NFS v3 and v4 served by the same component, register
NFS door at login broker only if v4.1 is enabled.

Acked-by: Paul Millar
Target: master
Require-book: no
Require-notes: no