Restrict cap modules to only cap ships (#1097)

* Restrict capital modules to capital hulls

* tweak comment

* Make a isCapitalSize property for modules

eos/saveddata/module.py

@@ -199,6 +199,10 @@ class Module(HandledItem, HandledCharge, ItemAttrShortcut, ChargeAttrShortcut):
         if self.owner:
             return self.owner.modules.index(self)
 
+    @property
+    def isCapitalSize(self):
+        return self.getModifiedItemAttr("volume", 0) >= 4000
+
     @property
     def hpBeforeReload(self):
         """
@@ -418,6 +422,11 @@ class Module(HandledItem, HandledCharge, ItemAttrShortcut, ChargeAttrShortcut):
         if isinstance(fit.ship, Citadel) and len(fitsOnGroup) == 0 and len(fitsOnType) == 0:
             return False
 
+        # EVE doesn't let capital modules be fit onto subcapital hulls. Confirmed by CCP Larrikin that this is dictated
+        # by the modules volume. See GH issue #1096
+        if (fit.ship.getModifiedItemAttr("isCapitalSize", 0) != 1 and self.isCapitalSize):
+            return False
+
         # If the mod is a subsystem, don't let two subs in the same slot fit
         if self.slot == Slot.SUBSYSTEM:
             subSlot = self.getModifiedItemAttr("subSystemSlot")