DIR: fixed a bug depending on the version-property of the register-service and...

DIR: fixed a bug depending on the version-property of the register-service and set-mapping operation.
	 refactored the operations to improve their readability.

git-svn-id: https://xtreemfs.googlecode.com/svn/trunk@1346 f8528748-c2c0-11dd-ba5c-d3b7c2b3b534