Added a poster column to posts

The database now has each post keep track of who posted it, the
"poster".  This is now displayed beneath the post itself in the index.
Added Admin Column and formatted time stamp.

I added a column for Users called "admin".  It is a boolean that
indicates if a user should have admin privelages.  Added user
admin@admin.com with "admin" set to true.  Also formatted the timestamp
on updating posts to be more readable.