New functions: service_data_files, collect_service_data, etc.
New functions: service_data_files, collect_service_data, etc.

- openbmctool_execute_command:
  - Code to support re-direct ">" in command_string
  - Minor doc fix

- New functions:
  - service_data_files
  - collect_service_data
  - health_check_fields
  - get_health_check

Change-Id: I1dd5753794b60026343eeeeff37ae07aad2beb5a
Signed-off-by: Michael Walsh <10404802c7de463f402c4a18638106ca1b12ef61@us.ibm.com>

openbmc/openbmc-test-automation,openbmc/openbmc-test-automation