Sorted errors wanted

[bernardito-luis]

When you customize your parser it is very likely that the order of raised errors will be broken.
Say you have some column that is required=True and you need some overall post-validation.
row1 pass requirement validation, but fails on post-validation
row 2 fails requirement validation
Thus in self.errors you will get messages in order: row2, row1

Maybe storing errors as objects with some attributes will make sorting simple, however it will require some additional memory.