Extended HostInfo functionality
* HostInfo is now mostly passed-through the AEP
* Agent provides a list of supported types
* Error strings can now be passed back from agent to API
* Add a HostInfo type for Date and Sysctl
* Add the ability to have specific tests for each HostInfo type
Merge pull request #531 from virgo-agent-toolkit/features/waldo_ohai_parity

Extended HostInfo functionality