add init script for rhel platform


The `default` recipe fails with the error below because the install does not create an init.d file.
This pull request provides the init script for the rhel platform.

```
  * service[ossec] action start[2013-10-31T05:17:56+00:00] INFO: Processing service[ossec] action start (ossec::default line 75)

    * service[ossec]: unable to locate the init.d script!
================================================================================
Error executing action `start` on resource 'service[ossec]'
================================================================================


Chef::Exceptions::Service
-------------------------
service[ossec]: unable to locate the init.d script!


Resource Declaration:
---------------------
# In /var/chef/cache/cookbooks/ossec/recipes/default.rb

 75: service "ossec" do
 76:   supports :status => true, :restart => true
 77:   action [:enable, :start]
 78: end
```