Add zero-arity versions of every-pred and some-fn

Zero-arity versions of these fns are useful in situations like the following:

Approach: This patch adds zero-arity versions of every-pred and some-fn with these semantics:

Patch: 0001-Add-zero-arity-variants-for-every-pred-and-some-fn.patch

• Patch adds zero-arity version

• Patch reformats docstring to 80 character width (matching other core fns) - comments are identical other than the addition of a final sentence stating behavior with zero-arity.

Screened by: