Merge branch 'release-1.7'
Merge branch 'master' of github.com:mfriedel/pydpiper into develop
* updated the logging setup, such that each executor writes its own logfile again. Pyro4 performs its own logging using the Python logging module. If not specified explicitly, all communication will be logged in the file "pyro.log". If you want this changed, you can either do that my setting environment variable (in or outside your program) or by setting the logging module parameter prior to importing Pyro4. Trying to change it after Pyro4 has been imported has no effect.
* also changed the format of the log filenames to make them slightly more human readable
* reverted the default memory allocation for pipeline_executors. Probably best set for in house computations (16G at MICe would not work well currently)
small bug fix
* fixed bug in re-rerunning the pipeline. With the move to Pyro4, and keeping track which executor handles which job, we can not use setStageStarted in skip_completed_stages anymore.