Added an empty class file for icinga2::objects so that we can keep all of the object types in their own subclass and directory hierarchy.
Added the package to Ubuntu 12.04 and 14.04 that contains the NRPE plugin, check_nrpe.
Added a basic defined type for Icinga 2 host objects; added an accompanying template.

This is really basic now. I'll add more parameters to it later on.
Merge branch 'feature/object_defined_types' into develop
Added parameters to specify the target file's owner, group and mode.
Added an array for a groups parameter and a hash for a vars parameter.
Add rendering of the groups = [] parameter into the host object ERB template.
Added a parameter for picking whether to install the Nagios plugins packages on nodes with the icinga2::server class applied.
Wrapped the server plugin install in an if statement so that installing the plugins packages depends on the parameter being set to true.
Added notes in the README about how to stop the icinga2::server class from installing the plugins packages.
Merge branch 'fix/duplicate_plugin_package_resources' into develop
Merge branch 'develop' into refactor/rename_client_to_nrpe

Merge the develop branch in so we can get the parameter that allows us to not install the plugin packages via the ::server class.
Renamed the icinga2::client class to icinga2::nrpe; this is mainly to accomodate other potential tyes of clients in the future, like NSCA or the Icinga 2 agent.
Deleted the duplicate client.pp and client/ directories.
Merge branch 'refactor/rename_client_to_nrpe' into develop
Merge branch 'develop' into feature/object_defined_types

Merging in develop so that we can get the icinga2::client --> icinga2::nrpe class rename and the parameter to control whether or not the plugins packages get installed via the icinga2::server class.
Added a hostgroup defined type.
Merge branch 'feature/object_defined_types' into develop
Updated comments in the host definition ERB template.
Renamed objects:: class to object:: since each defined type is for a single object type.