DON'T MERGE: Languages

An experimental branch with English and Google-Spanish menus, posted mainly for discussion and critique, but also because it's cute.

Natural language for menus, readLines, etc. reside in Languages/*.yaml files. Keys are abbreviated English, and values are full phrases in the appropriate language:

English.yaml:
```
"Leaving swirl now..." :
  "Leaving swirl now. Type swirl() to resume."
```
or Spanish.yaml
```
"Leaving swirl now..." :
 "Dejando remolino ahora. Escribe swirl() para reanudar. "
```
I think this is the, or at least a, usual way of handling multilingual content.

TODO: phrase.R

Definitely not ready for prime time.