Some small changes to Makefile to agree more with master
Some more commenting in SCF.f

Made some changes in the "actualiza rmm" section to take advantage
of matrix symmetries/algebra to do fewer/less expensive matrix multiplications

This section was sped up by about 40-50% (based on the hemo/caroteno tests)
A small change related to the previous commit - got rid of an
unneccessary scratch array
Similar matrix multiplication improvement to "coeff" section; a few more
comments