Move ruins templates to a new gaia/ruins/ subfolder.
Remove the "special" prefix since they are not special in any way.
Delete special_ruins.xml from rP10905 as it is identical to special_ruins_column_doric.xml from rP8574.
Differential Revision: https://code.wildfiregames.com/D990
Based on patch by: Nescio
Refs #4770, D989
Comments By: fatherbushido, leper