hawk: render conversion error tanks
now, if a conversion goes wrong,
the frontend can display a nice box with the printed tank.
imp/task: implement %become and %prayer pokes
an imp/task node can become identical to another
by recieving a [%become =pith] poke.
upon hearing the [%become =pith], a task sends
a [%prayer =pith] poke to it's target.
the target, upon hearing the [%prayer =pith]
will %make over =pith with its contents.
(and will do so recursively for kids as well)
