[zcash/zcash] Help users understand «transaction not mined» situations (#1959)

@str4d, if you have some spare cycles, could you look at the text in this [google doc](https://docs.google.com/document/d/1Ducz4iNN3OEC5WwQkQRa1z7wh96AukZKgmjcA0N2SK0/edit?usp=sharing) and wordsmith it to be more accurate if you see fit? If you don’t respond, we’ll just go ahead with our wording.

Запись редактировалась последний раз: May 7, 2018, 11:07 pm