SMB Data Loader: improve process for adding new data types or modifying current data type definitions

Currently, there are multiple steps needed to modify a current data type (such as adding a new column) :
1. modify the <type>-config.xml file to add the new column, and any validation information
2. modify the <type>Validator class to add the new column
3. modify the Create Table statement in StagingAreaDriver#tableStatement to reflect the change

Projected fix:
1. Not a bug - this was a feature to allow relatively easy changes to data types
2. Factor out the enum that names the columns, pull column number from <type>-config.xml
3. Pull these statements out of the code, move to external SQL scripts