Add configuration settings

[mejroslav]

You can add configuration settings to your code using configparser. This enables you to quickly change the datasources, algorithms etc without changing the code (say no more to huge commented code blocks).

Concept

1. Create config.ini file that looks like this:

   
   [general]
   datafile=path/to/datafile
   algorithm=rungekutta8
   outuput=path/to/output

[logging] level=debug logfile=path/to/logfile

2. The flow should be the following (not sure about fallbacks....)

```python
import configparser

config = configparser.ConfigParser()
config.read("config.ini")

...

self.Algorithm = config.get("general", "algorithm", fallback="RungeKutta8")
self.LogFile = config.get("logging", "logfile", fallback=None)

...
if self.Algorithm == "RungeKutta8":
    ...

You can also add default settings and much more...