httpd: Integrate handlers into spring wiring

The httpd service used a partial Spring wiring model where the bulk of the
service was still manually and dynamically instantiated. To integrate with cell
messaging, info extraction, admin shell, etc, the instantiation code tried to
glue the two models together, with lots of indirection and coupling. Worse, it
didn't actually work for admin shell integration. Thus the 'set update' command
was not actually exposed in the admin shell.

This patch reworks the entire service. The handlers are passed to Spring for
initialization, allowing them to hook into all the cell services without extra
glue code.

Life cycle management is moved into the HandleDelegator, just like for all
other Jetty handler collections.

Webadmin WAR files are no longer unpacked, resolving the issue with stale files
on upgrade. The httpd.container.webapps.tmp-dir property is now obsolete.

The arguments of the 'set webapp' command in httpd has changed: It now takes
the path to the WAR file, not the path to the directory containing the WAR
file.  Sites that have customized their httpd alias layout will likely have to
update their configuraiton.

The output of the info command has changed. The list of defined aliases is no
longer shown. The same information can be obtained with the existing 'ls alias'
command.

The changes are unfortunately so intrusive that backporting these fixes to
stable branches is unrealistic.

Target: trunk
Require-notes: yes
Require-book: yes
Acked-by: Karsten Schwank <karsten.schwank@desy.de>
Acked-by: Albert Rossi <arossi@fnal.gov>
Patch: https://rb.dcache.org/r/7436/
gplazma2-htpasswd: Avoid deprecated Guava classes

The plugin was incompatible with Guava 18 due to use of deprecated
classes that are removed in the new release.

This patch ports the plugin to Java 8.

Target: trunk
Require-notes: no
Require-book: no
Acked-by: Paul Millar <paul.millar@desy.de>
Acked-by: Karsten Schwank <karsten.schwank@desy.de>
Patch: https://rb.dcache.org/r/7465/
jetty: update webdefault.xml to adhere to new specification

The current xml stanza concerning security constraints does
not observe the new requirement that all HTTP methods be
specified.

This patch updates the xml namespace to point to the newer xsd,
and adds the missing omission stanza.

Testing:

Before application of patch, the following type of warning appears in the log:

05 Nov 2014 11:45:13 (httpd) [] ServletContext@o.e.j.w.WebAppContext@1db9683d{/webadmin,file:/var/lib/dcache/httpd/webadmin/webapp/,STARTING}{/webadmin.war} has uncovered http methods for path: /

The patch silences this warning.

Target: master
Patch: https://rb.dcache.org/r/7488
Request: 2.11
Acked-by: Paul
Require-notes: no
Require-book: no
Update to HikariCP 2.2.4

Required getting rid of DriverManagerDataSource as it doesn't support
setLoginTimeout.

Target: trunk
Require-notes: no
Require-book: no
Acked-by: Paul Millar <paul.millar@desy.de>
Patch: https://rb.dcache.org/r/7477/