Fixing the problem of zero imaginary part of the return value of spheHarm.
Fixing the problem of minus input value of m
Revert "Fixing the problem of minus input value of m"

This reverts commit 5561bdb0dd1e596e6bd74f16a17c9256206b795a.
mismatch of 'double complex' and 'complex double'
Merge branch 'master' of http://github.com/ZhanlinWang/zetaFuncCal
Adding the permission of minus input value of m.