Multistage implementation is incorrect

[jrmaddison]

In initialization of multistage checkpointing

pyrevolve/src/revolve.cpp

Lines 1170 to 1185 in 23dea91

	v = get_write_and_read_counts();
	sort(v.begin(),v.end());
	mid=v[snaps-sn_ram];
	// cout << mid << endl;
	for(int i=snaps-1;i>=0;i--)
	{
	if(v[i]>=mid && num<sn_ram)
	{
	where[i]=true;
	num++;
	}
	else
	{
	where[i]=false;
	}
	}

since v is sorted this always sets the last sn_ram elements of where to true, and the other elements to false, irrespective of the result of get_write_and_read_counts.

I think v should be copied before the sort (e.g. into w), and then the conditional replaced with

if(w[i]>=mid && num<sn_ram)