The syntax for defining salt functions in config or pillar files has changed to
also support the syntax used in module.run.
The old syntax for the mine_function - as a dict, or as a list with dicts that
contain more than exactly one key - is still supported but discouraged in favor
of the more uniform syntax of module.run.
Salt has had master-side ACL for the salt mine for some time, where the master
configuration contained mine_get that specified which minions could request
which functions. However, now you can specify which minions can access a function
in the salt mine function definition itself (or when calling mine.send).
This targeting works the same as the generic minion targeting as specified
here. The parameters used are allow_tgt and allow_tgt_type.
See also the documentation of the Salt Mine.
