0.8.14.20: Documentation madness, yet again

0.8.14.20: Documentation madness, yet again
            * Merge a partial rewrite of the docstring extractor,
               capable of handling a few more cases and providing
               nicer xref-names: @xref{Macro common-lisp:trace}
               instead of @xref{macro-common-lisp-trace}.
            * Reformat a few docstrings for nicer display.
            * Add documentation for LOAD-SHARED-OBJECT to the manual.
            * Move SAVE-LISP-AND-DIE to "Starting and Stopping"
               chapter. Say bye-bye to "Interface to Low-level
               Implementation."
            * Extract the version number for the manual from
               the SBCL the docstrings are pulled from, not
               version.lisp-expr.