webservices-rt.jar
webservices-tools.jar 
webservices-api.jar 

is to satisfy compile dependencies for web services. 
Once they are compiled this library is not needed. 
They are required to run a web service within servlet container - tomcat  
Standard JDK6 has this library in, it is relocated here to be able to use Ant tasks (WsGen, wsimport) for WS compilation
and make the project less dependant on the environment