customize servers java arguments

Servers java arguments should me customizable for various reasons : 
* jrockit in place of jre (1.6)
* add java system properties

orawls::domain could accept a hash argument (java_arguments) which keys are ADM, OSB, SOA and BAM.

hiera :
```yaml
domain_instances:
 'wlsDomain': 
  java_arguments: 
   ADM: "'-Xms1024m -Xmx1024m -Dweblogic.Stdout=/data/logs/AdminServer.out -Dweblogic.Stderr=/data/logs/AdminServer_err.out'"
  development_mode:     false
  log_output:           true
```
```
$domain_instances = hiera_hash('domain_instances')
create_resources(orawls::domain, $domain_instances)
```

Anyway, thanks for sharing your work