Disable HA when running from BrooklynRestApiLauncher

Otherwise HighAvailabilityManagerImpl throws NPE when creating
management record
Added CouchbaseLoadGenerator
Implemented couchbase load generator
Updated following PR comments
Displays a summary of HA status on web home page
Standbys respond 403 to non-GET/HEAD HTTP requests
support sensor feeds which set multiple sensors from a single request
Fix a couple of CSS errors
jsgui: Make standby servers obvious

Overlays a div blocking interaction with page when the server is a
standby. It can be deleted if the user really wants but the server
will also reject non-GET/HEAD requests.
jsgui: Rework HA model for tests

Starts auto-update from config.js rather than automatically.
rebind: don't call location.init too early
Adds testJcloudsTakesDotSeparateProperty
Adds+fixes testHandlesReferencingOtherEntityInPojoFieldsOfOtherTypes (WIP)
Fix sensor-subscription: equals based on name

- previously equality for sensor-subscription matching was on
  `sensor.equals()`, which takes into account name+type+description.
  This breaks things in yaml, where we want to just pass the sensor name.
- Therefore EntitySensorToken using sensor name for equality.
checkJavaHostnameBug: handle if .profile etc does stdout

- put markers around `hostname` output, so if there is extra stdout
  before or after then that will be ignored.
- hit this warning when using an unusual "brooklyn.ssh.config.scriptHeader"
Fix byob location's use of configure() on rebind
Change ssh.LOCAL_TEMP_DIR config from File to String
SshjTool synchronisation: added TODO and failing test

- and added a fix for one way that it fails due to the synchronization
  model; but more work required.
remove sandbox/mgmt project

fix a typo in jsgui/src/main/webapp/assets/tpl/app-add-wizard/required-config-entry.html
add pluginManagement tag to usage/dist/pom.xml to make Eclipse happier
Merge pull request #1388 from ahgittin/multi-value-polls

support sensor feeds which set multiple sensors from a single request