Add proper support for vbd resize using unit attention.
Added tag 0.11.0.399 for changeset 9f476ac2fbe1
Only log messages in DBG build
Turn some debug prints back on for free builds
Fix checksum problem on lso for xp/2003. Tidy up.
Fix xenvbd under xp
Added tag 0.11.0.402 for changeset 4de2eb034713