Added all the files, by 'svn cp', needed for the 1.2.10 branched ellipsoidal CS tensor code.
This is guessing the origin of files in https://www.ncbr.chemi.muni.cz/~kada/relax-1.2.10_cst.tar.
This maths_fns/ code comes from Pavel Kaderavek <kada att chemi dot muni dot cz>.