Code review comment for lp:~brendan-donegan/checkbox/bug960087_memory_compare_ram_devices

I've updated it to use the meminfo parser. As for the dmi parser, I agree with the fundamental principle of code re-use here, but I'm not too happy that every time I want to use a new attribute I have three files that need to be updated (the parser, the DmiDevice object and the script). I've also had to modify the dmi_resource script to prevent it crapping out because of the new attributes being used (which aren't universal so some checking had to be added). I'll update with the changes that need to be done to use the parser though and we can take it from there.