Began move to shspec::* function naming

This is motivated by Google's shell coding standards and will reduce the
odds of a naming conflict with other functions (which, of course, would
cause terribly odd and difficult-to-find bugs, in both our system and
others').

If this seems like it creates long, overly-verbose function names with no
relief in sight---you're right. I'll have a solution for that in a bit, as a
separate project. ...as a part of my never-ending, growing heap of projects.
{_sstack-=>shspec::stack::_}
Function name reformatting

See commit messages for more information. I will be worrying about variables
when I introduce another abstraction.