By: Trevor Jeffery Kristen Wiig should keep doing her thing, because it’s definitely working for her, and Welcome to Me shows it. Shira Piven’s Welcome to Me introduces itself masterfully: five minutes in and you know Alice Klieg (Wiig), her recently-unmedicated illness, and you have a good idea of how her life up to now has been.  And, how someone like her winning $86 million can have negative consequences. Alice throws money around like most…