Add Entities.attributeSupplier methods

- adds EntityAndAttribute tuple
- adds EntitiesTest
Add SameServerEntity
Add Zabbix entities to sandbox

- Work in progress - doesn't compile
- copied from github.com/cloudsoft/bt-hcc repo
SameServerEntity: incorporate review comments

- remove TEMPLATE_ID config key
Merge pull request #900 from aledsage/feature/import-goodies-from-bt-hcc

Feature: import goodies from bt-hcc repo