Need reversealias property for grind and plot labels
Grind and plot needs the reversealias property to be able to print out
the right thing. Without this, the result is the verb (%) form. We
really want the noun (%) form. This happens in msize-atom which will
strip the dollar sign off the noun form to produce the desired result.
Also added some comments on what the properties are need for.
This also means that all the places that called the function has been
replaced by ftake.
We also fixed a but in float evaluation of inverse_jacobi_sn(1.5,1/2).
We needed to convert the args to floats, but we weren't, so the
numerical lisp functions were seeing ((rat) 1 2) instead of 1/2.
But the other properties are needed. Otherwise things like
quad_qags(jacobi_sn(x,1/2) ...) and plot2d(jacobi_sn(x,1/2), ...)
fails with an error that it can't evaluate the function.