Replace 4alphaonly and 8alphaonly with the simpler and more generally

useful 32bpp and 16bpp hints.  (alphaonly was broken and had the effect
of 32bpp anyway).  These force a texture to 32bpp and 16bpp, overriding
the user's preference.

Use 32bpp for images that really do need 32bpp (where "dither" isn't
good enough).  Use 16bpp for images that really don't need 32bpp,
to save memory.

stepmania/src/RageTexture.cpp

@@ -38,11 +38,6 @@ void RageTextureID::Init()
 	/* If true, enable HOT PINK color keying. (deprecated but needed for
 	 * banners) */
 	bHotPinkColorKey = false;
-
-	/* This indicates that the image is a transparency.  This allows for
-	 * high-resolution, memory-compact transparent layers.  The diffuse
-	 * color will be used with no texture color.  (0, 4, 8) */
-	iTransparencyOnly = 0;
 }
 
 bool RageTextureID::operator<(const RageTextureID &rhs) const
@@ -53,7 +48,6 @@ bool RageTextureID::operator<(const RageTextureID &rhs) const
 	COMP(iMipMaps);
 	COMP(iAlphaBits);
 	COMP(iColorDepth);
-	COMP(iTransparencyOnly);
 	COMP(bDither);
 	COMP(bStretch);
 	COMP(bHotPinkColorKey);
@@ -70,7 +64,6 @@ bool RageTextureID::operator==(const RageTextureID &rhs) const
 		EQUAL(iMipMaps) &&
 		EQUAL(iAlphaBits) &&
 		EQUAL(iColorDepth) &&
-		EQUAL(iTransparencyOnly) &&
 		EQUAL(bDither) &&
 		EQUAL(bStretch) &&
 		EQUAL(bHotPinkColorKey);