Revert "Manually build .la-files to avoid the .cpp-files to be added to the distribution."
Otherwise the .so files don't contain the actual code for the modules

This reverts commit 659f973064d1fa992e7414cec70a9de78cd6e3aa.
Python: Updated unit tests
Python: Updated nonbonded ia
Python: Rename the interaction_data module to interactions
Python: Remove broken direct access to lj cap_radius
Python: Set/get global forcecap + unit test
Python: delete unnecessary file
Python: LennardJones interaction - handle shift="auto"
Python: Update lj_liquid.py sample script