Support array and hash for value to osx_defaults

When type is dict or dict-add, the value should be one or more key/value
pairs. When the type is array or array-add, the value should actually be
one or more values.

Conflicts:
	manifests/osx_defaults.pp
Fix failing test

Converting hash to array has unpredictable ordering of keys, leading
to test failing now and then. Use single key/value in test to avoid
this.