Currently, #readable?, #writeable?, and #executable? will incorrectly
return true if the file does not exist.
In addition, I took the opportunity to refactor the File resource to
make it easier to write unit tests and supplied a full unit test
suite for this resource.
processes('bash').user does not actually make much sense for a resource
that is a list -- different entries can belong to different users.
Analogous for processes('bash').state.
The attributes 'users' and 'states' expose the unique values
corresponding to that property of entries in the process list.
Fixes#295.
before, the resource would throw an exception when include_files
returned nil (i.e., [].flatten!)
added basic unit tests capturing the include_files behaviour
