Unused flag since 1.21

[Jezz]

Soren or Jeff: Any chance that the x2 defense vs air units flag from civ2 will be re-instated with the next version? With 1.21, you removed the "mounted unit" flag and its currently unused.....

This flag would be very useful for scenario and unit creation... land based mobile SAM unit is one that comes to mind, plus, it'll "fix" the Aegis, which as is right now, is useless.