Currently the various other/palisades_* files inherit from various wall templates. This patch introduces a new template_defensive_palisade.xml to remove duplication in the palisade files.
Minor tweaks:
- standardized palisade armour
- default capture points to 500 (same as tower), rather than city walls' 1200
- removed stone costs and stone loot
- added minor wood costs and default 10 wood loot
- village phase requirement