(AIX) Fix service resources on AIX (SRC provider)

Prior to this commit the SRC service provider was broken on recent
version of AIX (5.3, 6.1, 7.1). The SRC service provider was not able to
introspect running services nor was it able to enable/disable services.
This commit makes service introspection possible in addition to being
able to enable/disable specific services.

Sprintly: fix item:231, item:265, item:230, item:232, item:273, item:266
(AIX) Allow non-root users to introspect services

Prior to this commit, non-root users were not able to introspect
running services via the SRC service provider on AIX. The underlying
problem is the `commands` portion of the provider DSL was/is aslo
effectively a `confines`. The SRC service provider has many commands
that it uses, but non-root users may only execute about half of them.
This constraint is sensible for starting and stopping services; however,
listing status of services should be able to be done for non-root users,
and this provides feature parity for other platforms like Linux. This
commit alters the `commands` DSL method to the `optional_commands`
method so that the appropriate metaprogramming still happends, but
removes the `confines` portion implicit to `commands`, which results
in the SRC service provider being deemed suitable for non-root users
on AIX.
(AIX) Create acceptance tests for src provider

Prior to this commit, the acceptance tests for AIX's src service
provider were barely a shell of a test. This commit tests that the
service provider can
 * find a specific service
 * start the service
 * stop the service
 * enable the service
 * disable the service

The tests were also refactored to use the puppet_acceptance `teardown`
portion of the DSL so that if a test step fails, the temporary service
will be removed prior to the next test run, especially important because
the setup section will fail if the service exists already as AIX's
`mkssys` does not have a way to override the state of an existing
subsystem (service).
Merge pull request #1461 from jeffweiss/ticket/aix/231_fix_service_resources_on_aix

(AIX) Fix service resources on AIX (SRC provider)