New entrenchment graphics mod

[DRG]

I changed the sandbags to something like this for sp2ww2 back in 1998 and changed back to the sandbags a couple of releases later for much the same reasons mentioned here. Others have attempted this as well. I went back to the sandbags becasue, in the end, they were easier on the eyes and worked better in more cases on the majority of terrain types

But it never hurts for others to take a stab at this

Don