IPMI Manager new functionalities

This merge request separates two functionalities - the generation of substitutions files and the functioning of the IOC itself. In addition, added the ability to generate a json file describing the MTCA grid configuration which is used to generate db and OPI files using the python tool impygen.

The OPIs should be generated with ipmygen from now. Thanks to that, they will not contain any dynamic scripts that make them unuseable.

Additionally it closes #41 (closed), #42 (closed), #45 (closed), #49 (closed) , #50 (closed) , #52 (closed), #54 (closed), #55 (closed)