Update README building instructions
Merge pull request #248 from dlowe-net/update-readme

Update README building instructions
Adds engraved objects and engraver mobile special

An engraving is just a short piece of text attached to the object
which is displayed in inventory, item content, and equipment lists.
It can be used to personalize items, but otherwise has no effect.
Merge pull request #249 from dlowe-net/engraver-mob

Adds engraved objects and engraver mobile special
Fixes boolean logic in same_obj()
Merge pull request #250 from dlowe-net/fix-same-obj

Fixes boolean logic in same_obj()
Corrects materials that can be successfully engraved
Merge pull request #251 from dlowe-net/correct-engraving-materials

Corrects materials that can be successfully engraved