(tags-table-computed-list, tags-table-computed-list-for): New variables.

(tags-table-computed-list, tags-table-computed-list-for): New variables.
(tags-table-list-pointer, tags-table-list-started-at): Doc fixes.
(tags-table-parent-pointer-list): Variable removed.
(tags-table-check-computed-list, tags-table-extend-computed-list): New
functions.
(tags-find-table-in-list): Function removed.
(tags-table-list-member): New function replaces it.
(tags-verify-table): New function, broken out of visit-tags-table-buffer.
(tags-table-including, tags-next-table): Rewritten.
(visit-tags-table-buffer-cont): Variable removed.
(visit-tags-table-buffer): Overhauled.
(tag-exact-match-p): Disallow newline in tag string before \177.