client: Merged branch "mno-async_writes" into trunk ("include/libxtreemfs" and...

client: Merged branch "mno-async_writes" into trunk ("include/libxtreemfs" and "src/libxtreemfs"). Added "util/synchronized_queue.h".

git-svn-id: https://xtreemfs.googlecode.com/svn/trunk@3233 f8528748-c2c0-11dd-ba5c-d3b7c2b3b534