U/salnikov/dm 621

@fjammes: true, eventually we want single implementation of the parser, probably meaning that we want to wrap C++ implementation with swig. This needs some care because of dependencies (qserv and partition do not depend on each other today).
@ktlim: I would hope indeed that we can find existing configuration file format and libraries for it, but whatever I looked at (and Serge too I guess) has serious limitations or just plain ugly. I think one more or less standard thing is INI format, but even for that standard Python parser does not do what we need. Anyways, I'm open to suggestions, and Serge also said that he is not quite happy that he had to introduce new config file format.