Immutable auditd rules are now configurable.

Moved the rules into a template, and added a module level config value
for whether rules are immutable. If true, a '-e' line is included at
the end of the config file.
Correcting a handful of syntax errors.
ida-486: Flag to panic the machine on audit failure.

Default to false. Also cleaned up some whitespace.
ida-486: Use puppetlabs/concat to build audit.rules

This change introduces the cabability to have multiple
modules contribute to /etc/audit/audit.rules by using
the audit::rule defined type.

The original template is used as a 'begin' fragment
and an immutable option has been introduced which
must be the last rule, hence order=99.
ida-486: Always have an end.erb fragment

Aesthetic change only