Bug 1096332 - All content-related workflows broken on Agent

Create and initialize managers in order

Passes rhq-core-plugin-container tests rhq-core-plugin-container-itest tests.
Passes manual testing of an AS7 resource:
* events
* content
* measurement
* operation
(before and after restart of the plugin container)
JMX Plugin tests enhancements

Abstracted common logic of AS7 and Wildfly8 tests
Added JMX service resource measurement and operation tests for AS7 and Wildfly8

Made measurement and operation tests in JMXPluginTest run on all test JVM Server resources
[BZ 1132399] - Plugin config for group has the save button on the top - placing both buttons on the bottom of the page and making them blue
[BZ 1031730] - Dashboard graph group does not retain group configuration - SingleResourceGroupSelector component now pre-selects the group stored in user prefs
[BZ 1127654] - Patternfly theme: various minor UI issues - The height of popups for assigning a server or agent into affinity group was enormous.
rhqctl install was failing with issues like:
  "Could not complete storage cluster schema installation: Authentication error on host"

The issue was intermittent.  The problem seems to be that the latest
version of Cassandra is taking longer than earlier versions to
initialize its default files (and the default cassandra user).
This happens at first startup.  We start cassandra just prior
to installing the server, because the server install applies the
schema updates.  But it seems cassandra was not quite ready at
times.  This change simply introduces a short delay to allow
cassandra time to finish its first-startup-initialization.

Additionally, an unrelated fix to ensure the yaml file is
properly closed on config updates.
[BZ 1132400] - metrics load icon visible forever for storage nodes auto-group - processResponse() even if there are no metrics to remove the spinner icon
Bug 1126047 - Agent awaits shutdown of ProcessExecutor idle worker thread; should terminate immediately

There's no need to block the JVM while waiting for a process completion or pumping process streams
[BZ 1031730] - Dashboard graph group does not retain group configuration - removing one unnecessary call of doPostPopulateAvailableGrid(), adding i18n for a message from AbstractSelector, reducing visibility from public to protected
[1133112] Inventory Merge is slow and consumes a lot of memory when a parent has many children
In our continuing search for new planets, new civilizations, er, strike that,
our need for better performance, this change ensures we don't pull
child sets unnecessarily during inventory merge.  This is very important in
the given use case, but should benefit all inventory merge to some degree.
Bug 1127411 - WARN [Thread-6] (rhq.core.pc.plugin.PluginClassLoader)- Failed to purge embedded jars directory. Cause: java.io.IOException

Destroy Plugin Class Loaders only once (IOException came from the
directory being already purged)
[BZ 1028329] - Refresh button does not refresh metric data on autogroup - The refresh button for GroupMembersHealthView will invoke the refresh also on the GroupMeasurementTableView component.
Bug 1127413 + Bug 1127412

Make BaseComponent less verbose on metric collection issues. Still, log
problems at DEBUG level.
[BZ 1000173] - Missing Disabled icons (404 not found) - when resizing the portlet, SmartGWT change the icon to the '_Disabled' form, but the icon was missing for 'Package_16.png'. I've added all kinds of portlets and it was the only one missing.
[BZ 1020874] - Add subscriptions button on platform->Content->Subscriptions tab displays HTTP Status 404 in UI - adding the form action JS hack
[1035420] OOB content labels get cut off
This portlet could use some more TLC, but at least now the metric name should
appear in full.  Added some better formatting to the list entries.  Note that
LinkItem.setClipValue(false) needed to be set explicitly despite being the
documented default.
Bug 1127410 - WARN [ResourceDiscoveryComponent.invoker.daemon-10] (org.rhq.plugins.postgres.PostgresDiscoveryComponent)- PostgreSQL data directory (/var/lib/pgsql/data) does not exist or is not readable

Log at debug level in discovery code (which is called often)
Log problems with the config file only once when the resource component
is started

Also, some code cleanup
[BZ 1133739] Group OOB portlet link doesn't display graph.
[1006487] Manual autodiscovery is confusing
Changed to "Run Autodiscovery"
(cherry picked from commit eaf199722b103b98f9f04303364952d3c845d789)

Signed-off-by: Jay Shaughnessy <jshaughn@redhat.com>
[BZ 1128929] Update verbiage to clarify what files need to be updated.