Merge pull request #342 from shaitan/lts

Monitor: fixed build on lucid. (lts)
dnet_io_attr: added total_size field (without ABI changes), which contains total size of the read record. In particular useful when client asks for part of the object (by specifying size in read request).
read-callback: only run read recovery when we have read the whole object. Added read recovery dbug.
Monitor&Doxygen: Added code documentation.