Check for colliding EC numbers for complexes

[jeffkimbrel]

If two different genes have the same EC number, yet those two genes form a complex and are both needed, gator could erroneously call that reaction present even if one component was missing.

The --verify_db command could check for this and print out an error. Or, we can keep the EC column out of the calculations. I don't think it is used now anyway, and if it is it is only when using the --patric flag.