[Ecls-list] (documentation) fixes

[Maciek Pasternacki]

I just commited patches to src/lsp/helpfile.lsp and
src/clos/inspect.lsp which fix (documentation) and (setf
(documentation ...)) behaviour.

I patched (si::get-documentation) and added (defmethod documentation
((object function) doc-type) and appropriate (setf documentation)
method so that finding functions' docstrings from doc file works again.

I also got rid of infinite recursion bug in (defmethod (setf
documentation) (new-value (object symbol) doc-type)).  Setting
functions', generic functions' and methods' docstrings works now.

-- 
__    Maciek Pasternacki <maciekp at japhy.fnord.org> [ http://japhy.fnord.org/ ]
`| _   |_\  / { 2.718281828459045235360287471352662497757247093699959574966967
,|{-}|}| }\/ 62772407663035354759457138217852516642742746639193200305992181741
\/   |____/ 359662904357290033429526059563073813232862794349076... ( e )  -><-