JSON conf

The following PR adds a $json_conf parameter that can be toggled to create a JSON formatted lumberjack config.  Setting it to true will alter how the $hostname and $files parameters work.

NOTE: This relies on a function called sorted_json() which I found as a gist on GitHub and no license.  I've contacted the author regarding this.  The functionality is unusable without this.
ref. https://gist.github.com/halkeye/2287885

Additionally, this PR fixes some other minor issues I ran into while testing my changes
- An incorrect variable name in the lumberjack.erb file
- /etc/lumberjack is now created by the module. (Our RPM did not do that.)
- proper dependency handling in lumberjack::instance if $lumberjack::restart_on_change is false