Shperical BCs Bug Fix + Integration of rotations imporved
- Spherical BCs always running for every 912 solution
- cleaned up the code and added a forced stop if the spherical BCs are used with a solution which is not 102 or 912 (only two supporting the spherical joint). 
- deleted unuseful files
- methods to integrate rotations and displacements added and tested (lib.postpr)