Formal Charges

Prompted by the recent discussion about ionic liquids, I pushed some
changes which implement atomic formal charges (e.g. NH4 => +1 on N).
These can be set by bonding, edited by the atom properties extension,
and displayed with the label engine.

In general, I think the code does a pretty good job of interpreting
formal charges when they have not been set by the file format. Please
report bugs, since this is relatively new code “close to the deadline.”

I have also merged the Dalton input generator, even though it adds
more translatable strings.


P.S. Remember that Oct. 10th is a “bug-fix sprint” day. I’ve tried to
squash some today, and I’ll try to squash more tomorrow.