Replace native .options with jQuery .children()

Fixes aldeed/meteor-autoform#101

Given that jQuery is included in standard-app-packages I don't see any negative to making autoform dependent on it.

jQuery would have insulated autoform from this slight browser inconsistency, exposed by meteor's _.each patch (which I don't have enough of an understanding of to have an opinion on), with regards to HTMLOptionsCollection not being a "true" array in Safari. Therefore, I suggest moving forward that autoform make use of jQuery for DOM manipulation, instead of relying on native browser interfaces. Full disclosure, I'm not a huge user of jQuery currently, but this issue exposed me to a good reason why I should be.

Note, I simply added api.use('jquery') first in the list of api.use's as I couldn't seem to derive the ordering of them ... low priority obviously... but perhaps they could stand to be refactored.