feat(TU20/21): Implement la's TU21 patch file

This adds the following:

TU20:
1. Librarians now have a small chance to offer name tags for sale
2. Witches can now spawn at light level 7 or less in any biome or cave
3. Skeletons & Wither Skeletons now rarely spawn anywhere in the Nether

TU21:
1. Minecart entity limit increased

Minecraft.Client/LivingEntityRenderer.cpp

@@ -491,7 +491,7 @@ void LivingEntityRenderer::renderNameTag(shared_ptr<LivingEntity> mob, const wst
 	float s = 1 / 60.0f * size;
 
 	glPushMatrix();
-	glTranslatef((float) x + 0, (float) y + 2.3f, (float) z);
+	glTranslatef((float) x, (float) y + 2.3f, (float) z);
 	glNormal3f(0, 1, 0);
 
 	glRotatef(-this->entityRenderDispatcher->playerRotY, 0, 1, 0);