Create one parsing function for each stop
Create one parsing function for each stop

Fixes issue #19

The parsing closures created in the loop would share the same
environment, so often the data would be miscategorized. See
https://developer.mozilla.org/en-US/docs/Web/JavaScript/Closures#Creating_closures_in_loops.3A_A_common_mistake

Using a factory function for parsing binds the stop variable to
the correct value.

horsemeat/dublin-bus-tracker,horsemeat/dublin-bus-tracker