* gds.el: Add requirements: cl, comint, info.

	* gds.el: Add requirements: cl, comint, info.
	(gds-guile-program): New.
	(gds-start): When starting or restarting, kill captive if it
	exists.  Use gds-guile-program instead of just "guile".
	(gds-mode): Use widget minor mode.
	(gds-client-ref): New optional client arg.
	(gds-update-buffers): Don't call widget-setup.
	(gds-heading-face): New.
	(gds-insert-interaction): Various prettifications.
	(gds-heading-insert): New.
	(gds-choose-client): Check that numbers in client and gds-client
	are still valid.
	(gds-eval-expression, gds-apropos): Remove text properties from
	expression to evaluate.
	(gds-mode-map): Don't set widget-mode-map as parent.
	(gds-start-captive): Use gds-guile-program instead of just
	"guile".

	* gds-client.scm (install-breakpoints): Bugfix: avoid null lists
	in traversal.
	(eval-thread, gds-eval): Where expression has multiple parts,
	modify output to say which part is being evaluated.