Bug fixes with payperiod handling

budget.py

             raise Error
 
     def current_pay_period(self):
+        if self.delta == None:
+            self.pay_period_delta()
         self.find_pay_period(datetime.date.today())
 
     def next_pay_period(self):
             self.pay_period_delta()
 
         next_period = PayPeriod()
-        next_period.find_pay_period(self.end + self.delta)
+        next_period.find_pay_period(self.end)
         next_period.calculate_budget()
 
         return next_period
 
         beginning = pay_date
         end = pay_date
-
-        while date > end:
+        while date >= end:
             beginning = end
             end += self.delta