bug#10348: 24.0.92; Save and load window states

[martin rudalics]

> Actually there exists already a parameter that distinguishes between values
> needed for intra-session purposes and needed for inter-session purposes.
> It is the argument `markers' of the function `window-state-get'.  When 
non-nil,
> it returns internal values meaningful only in the current session.  When nil,
> it returns integer values safe to save and read in another session.
> This argument could be renamed to a more general name and used for
> other values besides markers.  Then a caller of `window-state-get'
> could decide whether its return value is intended for the same session
> or for intra-session purposes.

So we could add the `window-state-saved-parameters' variable Stefan
proposed and add parameters mentioned there only if the (probably)
renamed MARKERS argument is t or nil (whatever default we want here).

martin