Update to urllib2
Handle directory requests
Handle range requests, but do not download full file
Out tracebacks on error
Stop handling directory/index requests
Add a 5 second timeout for upstream requests
Remote mtime values are in seconds, truncate local mtime values
Return HTTP_PARTIAL_CONTENT status for range requests
Merge in nwra branch
Greatly simplify (and fix) master/slave operation.  Master always
stays the master, slave always stays slave.