Add print out of parameter names and values on error.

[jluastro]

It would be very handy to print out the parameter name and parameter values whenever an keyword error is thrown. E.g.

If this would also display: powfs.nwfs = [1 1] llts.ox = [-7 0 0 7 0]

it would make debugging much faster.

Thanks!

[lianqiw]

Fixed in 9b9284c.