rename R.toUpperCase and R.toLowerCase

1.0 is probably six months away. Between now and then we must agree on the name and type of each existing function. After 1.0 we're free to change implementations, and to add new functions in minor releases, but renaming functions will be off the table until 2.0. Thus, I'm keen to continue initiating naming discussions.

I consider this is a slight improvement. Shortening these names does not introduce ambiguity, and all else being equal I prefer shorter names.