Wt

To avoid this:

1. start your wt application with ---num-threads=1. This is usually acceptable during debugging.
2. reroute access logs to a file with ---access-log=somefile.log
3. reroute the application log to a file (see wtconfig.xml)

we could do something about access log messages running into each other, if required. This is however not trivial in all cases (multi-process deployments). I propose to implement this when this turns out to be problematic.