- added an ObjectSet (not modular) which is using a BitSet for efficient saving of objectNo's

- OSD- and object-selection separated from TransferStrategies
- new simple sequential prefetching strategy
- now xtfs_repl contacts OSDs for a new full replica, so they start to replicate
- new method for StripingPolicies which gives all objects for an OSD (e.g. all objects from one column in 
RAID0)
- moved some classes

git-svn-id: https://xtreemfs.googlecode.com/svn/trunk@919 f8528748-c2c0-11dd-ba5c-d3b7c2b3b534