Add citadel fittings to market browser, and get rid of some initial errors

eos/saveddata/fit.py

@@ -743,6 +743,10 @@ class Fit(object):
         capacity = self.ship.getModifiedItemAttr("capacitorCapacity")
         mass = self.ship.getModifiedItemAttr("mass")
         warpCapNeed = self.ship.getModifiedItemAttr("warpCapacitorNeed")
+
+        if not warpCapNeed:
+            return 0
+
         return capacity / (mass * warpCapNeed)
 
     @property

eos/saveddata/module.py

@@ -151,7 +151,7 @@ class Module(HandledItem, HandledCharge, ItemAttrShortcut, ChargeAttrShortcut):
     def isInvalid(self):
         if self.isEmpty:
             return False
-        return self.__item is None or (self.__item.category.name not in ("Module", "Subsystem") and self.__item.group.name != "Effect Beacon")
+        return self.__item is None or (self.__item.category.name not in ("Module", "Subsystem", "Structure Module") and self.__item.group.name != "Effect Beacon")
 
     @property
     def numCharges(self):

eos/saveddata/ship.py

@@ -43,7 +43,7 @@ class Ship(ItemAttrShortcut, HandledItem):
 
     def __init__(self, item, parent=None):
 
-        if item.category.name != "Ship":
+        if item.category.name not in ("Ship", "Structure"):
             raise ValueError('Passed item "%s" (category: (%s)) is not under Ship category'%(item.name, item.category.name))
 
         self.__item = item