refactor bulk insert and clean up logs

Bulk insertions were refactored to prefer row construction for bulk
inserts that are not empty. The actual sql generation was moved back
into the query-generator, and removed from sql-generator. Also a number
of console.log and console.warn's were moved over to using sequelize's
internal logging mechanism
merge
Merge branch 'mbroadst-bulk-insert-refactor' into feature/ms-sql-server