Omc port from log

[syntron]

OMC writes the ZMQ port into a file which must be found to get this information. Currently OMPython defines the file name in the Python code. However, this information is available in the log of OMC - why not use it?

This code replaces the old way of defining the port file with an evaluation of the log data.

Based on top of PR #295; this should be included in the next release (see #254)

[adeas31]

@syntron this needs to be rebased before we can review it properly. Seems like the actual change is in commit which looks fine to me. I looked into the compiler code and indeed the log contains the file path and we don't need to construct it.