added recent changes concerning the attachment of time series sensor data to station objects from ogs5 to ogs6, added RapidXml as a small library for reading XML files from console application, added existing xml schema files

This reverts commit 05677165.

Conflicts:
	FileIO/XmlIO/XmlGspInterface.cpp
	README.md

in order to make the name of libraries, namespaces and directories more consistent the Base directory is know named BaseLib

- added test programm for solving a linear system with CG-method
- time measurement is at the moment OS dependent!
- added Base folder
- added GeoLib folder
- added files in MathLib folder - restructured MathLib folder