Make texture policies explicit.

Never keep banner textures loaded.  We'll be using enough memory with
the preloads, and it's not needed.

stepmania/src/RageTexture.cpp

@@ -83,6 +83,8 @@ RageTexture::RageTexture( RageTextureID name ):
 //	LOG->Trace( "RageTexture::RageTexture()" );
 
 	m_iRefCount = 1;
+	m_Policy = TEX_DEFAULT;
+	m_bWasUsed = false;
 
 //	SetActualID();
 	m_iSourceWidth = m_iSourceHeight = 0;