Exclude impossible campaigns

[Nollasko]

I think it would be more effective if the miner did not farm campaigns that would end before the miner could get them

[Windows200000]

I think #70 should work, but I am a little scared it could refuse to mine campaigns that are only partly possible.

[Windows200000]

Yeah....

[Windows200000]

It is there, but it's not as straight forward to get to it.

[Windows200000]

Well, it needs a function to loop through it and find the lowest. I don't have the time to set that up right now, especially since there are functions with the same name, that do very similar, tho not exactly the same stuff in different classes.

If anyone else can do it, I'll review and merge.

[Windows200000]

@Nollasko thinking on it a bit more, the issue is still that the miner can sometimes incorrectly guess progress, as described in #63. This could then also lead to a minable campaign not being mined.

I don't think it makes sense to work on this feature until we find a solution to the above-described issue.