Updated Puppet to support following additional agent parameters:
* Pluginsync - defaults to true
* Splay - defaults to false
* Runinterval - defaults to 30. 

Added as parameters to init.pp so that can be set on class call. 
Updated puppet.conf.erb template to handle additional properties.
* Updated default run interval to seconds. 
* Converted lookupvar to use top-level param scoping.