Revert "Make host nillable but don't allow it to be committed to the database as nil unless we're using Oracle"

This reverts commit c3568568fc0a0c6b82069f10484768167332065c.
Revert "Updated model tests to allow nil for host but dis allow nil from making it into the database unless we're using oracle."

This reverts commit bbbe0cc5e3465c99e9fca8edbc7e3315a039269b.
Revert "Adding support for oracle varchars that cannot tell the difference between null and """

This reverts commit 627f83b515422223bae31611a342c00de8187bdd.