Add parameter 'v8plus' for rsyslog version 8+

There has been some significant config changes in versions 8+ of
Rsyslog, one of which is causing deprecated warnings with the Puppet
module. This commit adds are class boolean parameter 'v8plus' to signify
if the version of Rsyslog is version 8 or greater.

Also, the deprecation warning is fixed (correct syntax is used).
ignore .DS_Store files
add parameter for setting the remote forward format, fixes #46
add fact for rsyslog version from pr #50, refs #87
Use fact for rsyslog version instead of param

With the introduction of the rsyslog_version fact, it seems more
consistent to use that to determine what version of the config to use.

The fact has also been updated to support FreeBSD (although not well
tested)
Revert "Add parameter 'v8plus' for rsyslog version 8+"

This reverts commit 18a16ca041469d99bc0c5d27c46db62a06903ed8.
Update spec tests to support rsyslog_version fact

With commit 9fcacf58, the module uses the rsyslog_version fact in
templates. This commit updates the spec files to run cleanly with this
fact.
Issue #84: Document *_package_name usage

Document that setting false for package_name prevents the modules from
managing the package.
* Fix error in template if rsyslog_version fact is not present