Partially reverting the $warn/$warn_message param split from eaf8407 as this
change was unnecessarily API breaking. Instead, we are adding string/bool type
validating to the $warn parameter and deprecation warnings for the usage of
stringified boolean values (eg, 'true', 'on', etc.). In a future major release,
the logic can be simplified to treating all string values as a warning message.
There's no need to allow the ownership/permissions of a fragment to be set as
the concat define sets ownership/permissions on the final aggregated file.
The use of $::id to set the default user/owner and group has caused
multiple bugs in the past, is incorrectly used to infer the egid,
introduces a dependency on the `id` fact, and provides no functionally
that can't be accomplished by passing `undef` or not setting the
respective params on the file & exec types.
A possible alternative would be to introduce a dep on the $::gid fact
but that would mean the entire module would depend on a version of
facter than hasn't shipped yet (unworkable) or to add a gid/egid fact
into this module (ugly).
