(app_push): Save saved_input in allocated buffer.
	(app_pop): Restored saved_input.
	(do_scrub_chars): Change get parameter to take char * and int as
	arguments.  Change GET macro to pass input_buffer to get
	function.  Don't save input into allocated buffer.
	* as.h (do_scrub_chars): Update declaration.
	* input-file.c (input_file_get): Change to take char * and int.
	Read data into passed in buffer.  Remove static buffer.
	* read.c (scrub_from_string): Change to take char * and int.  Copy
	data into passed in buffer.