Add EntityLocal.modifyAttribute(AttributeSensor, Function)

- For atomic (sequential) updates to an attribute, where the new
  value is computed from the old value.
Fix ServiceStateLogic updating map

- Don’t modify the existing attribute value. Instead take a copy
  and modify that.
- Also fixes (and tidies) assertions in
  brooklyn.rest.client.ApplicationResourceIntegrationTest
- BrooklynRestResourceUtils: don’t propagate to the top-level app
  the service_up, service_not_up_indicators, etc.
  These are populated automatic by app.initEnrichers, which looks
  at the child entities.
This closes #290