CSV Upload History feature

Every time an admin uploads a new CSV table definition (IE attributes, projects),
store the CSV in the database.  Provide a UI for managing
these versions on admin/data.aspx.  Include human readable hash of version
to assist in managing revisions
Bugfix - missing table columns in attribute upldr
use regular, not temporary table
add user id to revision history
single class for Attribute upload

got rid of the auxilary class for attributes upload.
Merge pull request #32 from azavea/topic/CsvUploadHistory

CSV Upload History feature