[WPS-4.0] Integrate integration testing for WPS4R module

[nuest]

the module has no configuration for failsafe yet, so...

• move the common parts of the current configuration from the webapp module to parent pom pluginManagement
• re-add configuration to webapp module
• add configuration for failsafe to WPS4R module
• see if the IT is picked up in mvn verify
• see if the WPS4R it's can be adapted to check for a locally available RServe instance, e.g. by making that a resource, and only execute them if Rserve is running
  • remove exclude
  • test should only be made once for all ITs