[bug 1033986] Update sanitization scripts fail gracefully on error.

Bash script now creates 4 databases instead of 2:
     - sanitize_dev_$DB
     - sanitized_dev_$DB
     - sanitize_stage_$DB
     - sanitized_stage_$DB

     mysqldump is run against the sanitized_* databases,
     i.e. sanitized_stage_mozillians_org and sanitized_dev_mozillians_org

Python SQL generation script was altered to:
     - Execute all generated SQL into a transaction, so it's either all
       executed or nothing executed.
     - The last command of the sanitization process is to rename the database
       E.g sanitize_dev_mozillians_org becomes sanitized_dev_mozillians_org
Drop waffle tables during sanitization.
Merge pull request #1049 from glogiotatidis/anon

Update anonimization scripts.