Updated fundings in README.md
doc: revised OSD health script description
servers: updated javadoc in StorageLayout
foundation, servers: renamed ONCRPC to PBRPC
removed XtreemOSAuthProvider (not compilable without further XtreemOS sources)
servers: skip empty path components (fixed issue #290)
client/benchmarks: Add cpp benchmark tool.

The benchmark tool does only support sequential write tests for now.
client/benchmarks: Create default Volumes if none are given as parameters.
client/benchmarks: Share one client between all benchmarks.

Libxtreemfs for C++ doesn't allow for multiple clients in one instance
so the clients have to be shared between all benchmarks. This is
different from the Java benchmark tool, where every benchmark
starts it's own client.
client/benchmarks: Remove unnecessary shared_ptrs.