Support tabbing through controls in modals, popovers, and selects

I rebased the work that @thangdinh did, as he will be unable to work on this for a while. Not very familiar with the code, so hoping that someone else is.

@cyril-sf @azirbel @Dylnuge @jpriceAddepar 
I didn't finish this thought but may be wrong anyway. Will get back to you; never mind in the meantime ;)