MainLinks Fix

See !4069 (merged).

Also made things easier to read in my opinion. In particular, no more ll or sl or cl instead of just accessing .length Yes, I know you lose a microsecond of efficiency, but it's so much easier to read and understand.

Also used standard i and j for indexing variables. Now that there's no chance of falling through to unintended passages, I prefer to use standard indexing variables instead of function/passage specific ones.

Also no shortening slave to s or similar inside forEach loops. Again, just makes it easier to understand what's intended.