Update the docstrings in the cl emodule.

Update the docstrings in the cl emodule.

This adds/updates the docstrings for the DEFUNs in the cl emodule.  I've
basically just lifted the doctrings from the equivalent functions/macros
in cl*.el.

	* modules/cl/cl-loop.c (Fcl_loop): Add a docstring.
	(Fcl_doX): Typo in docstring.
	(Fcl_dotimes): Update docstring.
	(Fcl_dolist): Ditto.
	(Fcl_do_symbols): Ditto.
	(Fcl_loop_sentence): Direct folks to #'cl:loop docstring.

	* modules/cl/cl.c (Fcl_pop): Add a docstring.
	(Fcl_push): Ditto.
	(Fcl_pushnew): Ditto.
	(Fcl_eql): Ditto.
	(Fcl_list_): Ditto.
	(Fcl_tailp): Ditto.
	(Fcl_ldiff): Ditto.

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