Salting function sucks at creating edges

[andresfchamorro]

Our salting function salt_long_lines isn't working properly as noted by @rbanick. I've looked into this and will commit some changes to fix it.

1. Nodes are salted correctly, but long edges are dropped in the resulting graph, which means that "salted" edges are not being created correctly. The part of the script that re-adds salted edges is in a try statement, so errors in the edge creation / data attribution are not being captured.

2. The function is also projecting every edge one by one. Fixing that will make it run a lot quicker.

On a related note, I was testing this with a graph with edges that contained lists [] in their wkt attribute. This is a product of the clean network function. Adding rectify geometry after the second custom_simplify should fix this.