The string stored is now strlen(s)+1, with length 0 indicating NULL.
Increment savegame version for this new format.
Old savegames are fixed by assuming VAL_STRING should never be NULL.
WME Lite completely.
(This also breaks compatibility with savegames from ScummVM prior to this commit, AND resets the
Savegame-version, older savegames will have differing MAGIC-numbers in their headers, and will thus
not be recognized).