Arity test case using f:make-ref

In place of manual specification.
`f:arity' now considers partial applications
`arity.xsl' stylesheet combined with ref functions into `ref.xsl'

These are strongly related---they operate on the same abstraction.
apply-gen now uses `f:make-ref'

We're essentailly macro-expanding the `f:make-ref' call.  :)
Partial applications now manipulate fnref arity

Previously, a separate `@partial' attribute was added to the ref and the
`@arity' maintained.  Unfortunately, this coupled `f:arity' with
`f:partial', which is unnecessary, considering that partial application is
supposed to conceptually yield a new function, which should be transparent
to `f:arity'.
`f:set-args' setter and `f:args' accessor implemented

As operations on dynamic function references become more complex, and since
evolution of the reference structure is planned to evolve, maintaining an
abstraction is vital for both grokking and maintenance.
`f:{unshift,push}-args' added
Partial applications now defined in terms of ref mutators
More comprehensive fnref abstraction

This will allow the implementation to evolve transparently.  And it will be
evolving.