Remove confusing ITEM_ARMOR_LAMELLAR. Lamellar leather armor remains.

Almost every reaction in the game that produces 'lamellar armor'
creates '[lamellar leather] armor', which is 'armor' crafted from
'lamellar leather'. However the boneyard, and some very rare
religious/expedition reactions could create 'lamellar armor',
which was an entirely different thing.

This change keeps the lamellar leather armour pieces that everybody
uses, and removes the confusing and almost entirely unused 'lamellar
armor'.

This also explains why I could never get my military to have uniforms
of lamellar leather armor; I was instructing them to wear 'lamellar armor'
rather than 'armor' of material 'lamellar leather'. :)