Consider task duration in ordergroup stats.

* Also added duration to task template in workgroup task_duration.

test/fixtures/groups.yml

@@ -17,6 +17,8 @@ bananas:
   contact_phone: 030 123132456
   contact_address: Waldermarstrasse 43, 10988 Berlin
 
+
+
 # == Schema Information
 #
 # Table name: groups
@@ -25,7 +27,7 @@ bananas:
 #  type                :string(255)     default(""), not null
 #  name                :string(255)     default(""), not null
 #  description         :string(255)
-#  account_balance     :decimal(8, 2)   default(0.0), not null
+#  account_balance     :decimal(, )     default(0.0), not null
 #  account_updated     :datetime
 #  created_on          :datetime        not null
 #  role_admin          :boolean         default(FALSE), not null
@@ -43,5 +45,6 @@ bananas:
 #  contact_phone       :string(255)
 #  contact_address     :string(255)
 #  stats               :text
+#  task_duration       :integer         default(1)
 #