Deprecate 'wp' group and introduce a new group 'text'

Deprecate 'wp' group and introduce a new group 'text'

* lisp/textmodes/tildify.el (tildify):
* lisp/textmodes/text-mode.el (text-mode-hook):
* lisp/textmodes/table.el (table):
* lisp/textmodes/rst.el (rst):
* lisp/textmodes/refer.el (refer):
* lisp/textmodes/refbib.el (refbib):
* lisp/textmodes/picture.el (picture):
* lisp/textmodes/nroff-mode.el (nroff):
* lisp/textmodes/enriched.el (enriched):
* lisp/textmodes/bib-mode.el (bib):
* lisp/progmodes/ebnf2ps.el (ebnf2ps):
* lisp/nxml/rng-valid.el (relax-ng):
* lisp/view.el (view):
* lisp/ps-print.el (ps-print):
* lisp/printing.el (printing):
* lisp/outline.el (outlines):
* lisp/lpr.el (lpr):
* lisp/delim-col.el (columns): Use 'text' group instead of 'wp'.
* lisp/cus-edit.el (wp): Remove the "text" tag.
(text): New defgroup, inherits from the deprecated 'wp'.
(outlines): Remove, in favor of the definition in outline.el.
(tex): Inherit from 'text'.
Suggested by Drew Adams <drew.adams@oracle.com>.  (Bug#24549)