Feature/983 data importer

# Warning

# Info

The release includes the new NPSP Data Importer, which helps you easily import your data into the Nonprofit Starter Pack

# Issues

Fixes #983 
Fixes #1020 
Fixes #1015 
Fixes #1014 


You don't need a list for this, you can just do delete [select id from DataImport__c], but you'll also want to add a row limiter to it [select id from DataImport__c limit 10000];   

Same with line 21 above