* Encore on the voting screen! Appears randomly once unlocked in the same slot...

* Encore on the voting screen! Appears randomly once unlocked in the same slot as that which sometimes represents a gametype change (odds inflated for testing purposes).
* A better representation of an Encore level, now with inverted graphics (a special remapping we can now use elsewhere whenever if we want!) and a floating Ruby!
* Decouple encore's setting from cv_kartencore on mapload. Instead, bake it into D_MapChange and related, which will only some of the time be fed by cv_kartencore's value.
* Encore mode now has a special mapheader palette setting, "encorepal", rather than using the same one as non-encore.