As requested in D1342, this patch renames the four /maur* folders:
- art/actors/props/structures/mauryans/ → .../mauryas/
- art/actors/structures/mauryans/ → .../mauryas/
- art/actors/units/mauryans/ → .../mauryas/
- simulation/data/technologies/mauryans/ → .../mauryas/
Subsequently I did a grep to find and correct all occurrences.