lisp/frameset.el: Convert `frameset' to vector and add new slots.

lisp/frameset.el: Convert `frameset' to vector and add new slots.
(frameset): Use type vector, not list (incompatible change).
Do not declare a new constructor, use the default one.
Upgrade suggested properties `app', `name' and `desc' to slots `app',
`name' and `description', respectively, and add read-only slot `timestamp'.
Doc fixes.
(frameset-copy, frameset-persistent-filter-alist)
(frameset-filter-alist, frameset-switch-to-gui-p)
(frameset-switch-to-tty-p, frameset-filter-tty-to-GUI)
(frameset-filter-sanitize-color, frameset-filter-minibuffer)
(frameset-filter-iconified, frameset-keep-original-display-p):
Doc fixes.
(frameset-filter-shelve-param, frameset-filter-unshelve-param):
Rename from frameset-filter-(save|restore)-param.  All callers changed.
Doc fix.
(frameset-p): Adapt to change to vector and be more thorough.
Change arg name to OBJECT.  Doc fix.
(frameset-prop): Rename arg PROP to PROPERTY.  Doc fix.
(frameset-session-filter-alist): Rename from frameset-live-filter-alist.
All callers changed.
(frameset-frame-with-id): Rename from frameset-locate-frame-id.
All callers changed.
(frameset--record-minibuffer-relationships): Rename from
frameset--process-minibuffer-frames.  All callers changed.
(frameset-save): Add new keyword arguments APP, NAME and DESCRIPTION.
Use new default constructor (again).  Doc fix.
(frameset--find-frame-if): Rename from `frameset--find-frame.
All callers changed.
(frameset--reuse-frame): Rename arg FRAME-CFG to PARAMETERS.
(frameset--initial-params): Rename arg FRAME-CFG to PARAMETERS.
Doc fix.
(frameset--restore-frame): Rename args FRAME-CFG and WINDOW-CFG to
PARAMETERS and WINDOW-STATE, respectively.
(frameset-restore): Add new keyword argument PREDICATE.
Reset frameset--target-display to nil.  Doc fix.

lisp/desktop.el (desktop-save-frameset): Use new frameset-save args.
Use lexical-binding.