* expect.scm: (expect-regexec): new procedure, use it in

	* expect.scm: (expect-regexec): new procedure, use it in
	expect-strings to fix the => syntax under the new regex system.
	(top): include regex module in define-module statement.
	* (error-catching-loop): new local variable "interactive".  if
	#f, abort terminates the process.
	(set-batch-mode?!, batch-mode?): new closures, defined in
	error-catching-loop.  the names are from scsh.