Check for zero probability

[oaa3wf]

Is there any chance we could add a statement to the following effect after lines 192 & 206 in action.jl

if po == 0
continue
end

It may save some time for large statespace pomdp's.

[Zachary Sunberg]

Seems like a good idea to me. Also @dressel, where are spi and si being used? They don't seem necessary

[Louis Dressel]

I can't think of a reason not to do it.

@zsunberg Yeah they seem unnecessary. They might be left over from before discrete belief was reformed and we used actual state indexes. The simpler for sp in state_list should work.

@oaa3wf Do you want to make the changes and do a pull request? Otherwise Zach or I will take care of it.

[oaa3wf]

Yeah I'll make the changes, I might not get it it till the end of the day though.