Improve and simplify a few interactive defuns

Improve and simplify a few interactive defuns

For a few of the interactive functions I've moved the arg handling into
the interactive form.  I've also bound iso-left-tab (shift-tab) to
.#'emoney-backward-field as a logical match for tab on
.#'emoney-forward-field.

	* emoney.el (emoney-go-to-bank): Remove arg and simplify.
	(emoney-version): Simplify.
	(emoney-switch-to-account): Make arg non-optional and simplify.
	(emoney-mode-map): Bind iso-left-tab to #'emoney-backward-field.
	(emoney-transfer-funds): Make args non-optional and simplify.
	(emoney-new-account): Make args non-optional and simplify.
	(emoney-setup-control-buffer): Use #'call-interactively in a
	couple of the widgets because of changes in arg handling in
	.#'emoney-new-account and #'emoney-transfer-funds.

Signed-off-by: Steve Youngs <steve@sxemacs.org>