module_plugin for external agents doesn't set execute permission bit

[optiz0r]

All files installed by mcollective::module_plugin are installed with the same mode which defaults to $mcollective::plugin_mode=0644. This prevents external agents from being marked as executable, which in turn prevents choria-server from activating the agent.

Setting mcollective::plugin_mode=0755 allows choria-server to activate the agent, but at the cost of making all files distributed by plugin_module executable (including DDL files).