More updates to the Text chapter of the Emacs manual, and related nodes.

More updates to the Text chapter of the Emacs manual, and related nodes.

Make the documentation of Enriched Mode shorter, since it's
practically unused.

* text.texi (TeX Mode): Mention AUCTeX package.
(TeX Editing): Add xref to documentation for Occur.
(LaTeX Editing): Add xref to Completion node.
(TeX Print): Fix description of tex-directory.
(Enriched Text): Renamed from Formatted Text.  Make this node and
its subnodes less verbose, since text/enriched files are
practically unused.
(Enriched Mode): Renamed from Requesting Formatted Text.
(Format Colors): Node deleted.
(Enriched Faces): Renamed from Format Faces.  Describe commands
for applying colors too.
(Forcing Enriched Mode): Node deleted; merged into Enriched Mode.

* frames.texi (Menu Mouse Clicks): Tweak description of C-Mouse-2.

* display.texi (Colors): New node.

* cmdargs.texi (Colors X):
* xresources.texi (GTK styles):
* custom.texi (Face Customization): Reference it.

* glossary.texi (Glossary): Remove "formatted text" and "WYSIWYG".
Link to Fill Commands for Justification entry.