Commit Briefs
venti: fix usage to match manuals
R=rsc CC=plan9port.codebot http://codereview.appspot.com/4576041
venti: import changes from plan 9
R=rsc CC=plan9port.codebot http://codereview.appspot.com/4523057
R=rsc CC=plan9port.codebot http://codereview.appspot.com/4576041
R=rsc CC=plan9port.codebot http://codereview.appspot.com/4523057