* General: A lot of typo, texinfo markup and layout corrections.

	* General: A lot of typo, texinfo markup and layout corrections.

	* scheme-data.texi (Arithmetic): Clarified docs for - and /.
	(String Modification): Removed docs for C functions
	(scm_substring_move_right_x etc.)
	(Keyword Procedures): New section documenting the keyword
	procedures from boot-9.scm.
	(Vectors): Moved the section before the non-standard data types.

	* data-rep.texi (Defining New Types (Smobs)): Adapted description
	of smobs and proocedure creation to new terminology.
	(Describing a New Type): Removed mentioning of
	scm_make_smob_type_mfpe from smob function list and added
	deprecation notice for this function.
	(Creating Instances): Added description and macro docs for smobs
	with 2 or 3 data cells.
	(Garbage Collecting Smobs): Removed old docs for SCM_GCTYP16.
	(Garbage Collecting Simple Smobs): Added some clarification about
	usage and usefulness.
	(Non-immediate Datatypes): Changed R4RS reference to R5RS.
	(Vector Data): Document type-specific accessors.