Option to not automatically approve assignments when creating HIT

[IanEisenberg]

Right now the automatic delay doesn't work, and we should probably remove it because of this. While automatic acceptance of HITs is generally good, there should be an ability to completely remove this.

Specific case I am thinking about - I am setting up Dummy HITs to pay some people who had problems. While qualifications can mostly control who has access, it is possible that one of my "Ian" workers takes a task meant for another "Ian" workers. I'd like to be able to check that and approve manually rather than risk automatically paying someone doing a dummy task not meant for them.