WINTERMUTE: Redo the way floats are saved, break savegame compatibility with 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).
WINTERMUTE: Force the screen to black after loading/saving.
WINTERMUTE: Avoid using ldepxf/frexpf
GRAPHICS: Let JPEGs pixelformat state 0 alpha bits.
WINTERMUTE: Apply color-key if no alpha-channel is present

(Instead of using the bpp to detect it).
WINTERMUTE: Avoid applying color-keys to ALL images with bpp >= 3.
CONFIGURE: Fix build under et_EE locale

Freetype-config reports a broken include dir
when et_EE locale is used. We set LC_ALL
and LANGUAGE to "C" explicitly like autoconf
does to force consistent behavior.