trade.py upgraded to be able to be unpickled. (#406)

* trade.py upgraded to be able to be unpickled.

* Excluded .idea from .gitignore

* Fixed .gitignore

* Delete backtrader.iml

* Delete profiles_settings.xml

* Delete modules.xml

.gitignore

@@ -67,3 +67,5 @@ samples2/
 
 # Ignore test files in Datas
 datas/*.py
+
+.idea/

backtrader/trade.py

@@ -56,7 +56,7 @@ class TradeHistory(AutoOrderedDict):
     '''
 
     def __init__(self,
-                 status, dt, barlen, size, price, value, pnl, pnlcomm, tz):
+                 status, dt, barlen, size, price, value, pnl, pnlcomm, tz, event=None):
         '''Initializes the object to the current status of the Trade'''
         super(TradeHistory, self).__init__()
         self.status.status = status
@@ -68,6 +68,13 @@ def __init__(self,
         self.status.pnl = pnl
         self.status.pnlcomm = pnlcomm
         self.status.tz = tz
+        if event is not None:
+            self.event = event
+
+    def __reduce__(self):
+        return (self.__class__, (self.status.status, self.status.dt, self.status.barlen, self.status.size,
+                                 self.status.price, self.status.value, self.status.pnl, self.status.pnlcomm,
+                                 self.status.tz, self.event, ))
 
     def doupdate(self, order, size, price, commission):
         '''Used to fill the ``update`` part of the history entry'''