foundation: Added ErrorResponse util which allows to add an additional message...

foundation: Added ErrorResponse util which allows to add an additional message in front of the field "error_message"
servers:
- Added details to error message which is shown when the replica state was not received from a majority of replicas during the replica reset.
- Added own max object version to debug output when primary sends out replica state request to backups.

git-svn-id: https://xtreemfs.googlecode.com/svn/trunk@2752 f8528748-c2c0-11dd-ba5c-d3b7c2b3b534