psp refactoring and beginning of BTO run input file

Moved 3 current psps out of the BTO project and into a dedicated psp
directory in the top level of the repo. That should make it easier to
prevent duplication of psps across projects. Also added a psp library
that can be unzipped to get psps for new atoms as needed.
.gitignore update and extra info in input file

.gitignore stopped ignoring 'tmp_' prefix files as they are now created
in the work dir. Found pdf excerpt of section 1.17 from 'Basic Solid
State Chemistry' by Anthony R. West detailing structure of BTO and other
perovskites. Gives red coord vects and lattice params at room temp.
Added file manifest for structure optimization run