minor text fixes

[loriab]

Fix a couple typos and correct set_solid_harmonics_ordering advice after new comment in #285 initialize.h

[loriab]

fwiw, Psi4 has been using set_sho after initialize for months https://github.com/psi4/psi4/blob/master/psi4/src/core.cc#L1060-L1068 without problems. gtk that's not advised; I'll switch it around.

[evaleev]

fwiw, Psi4 has been using set_sho after initialize for months https://github.com/psi4/psi4/blob/master/psi4/src/core.cc#L1060-L1068 without problems. gtk that's not advised; I'll switch it around.

as long as it's immediately after it's fine ... but it's easier in the dox to say before ... passing as an arg to initialize would be best, of course, but I understand the python issues (would giving verbose argument a stronger type solve that issue?)