Refactor travel's CSV importer using d3.dsv and making it more flexible.
- It accepts any delimiter among tabs, comma and semicolon,
- The column order does not matter anymore, BUT the columns have to be properly labelled ! (this was already needed for the GESlab format but not for the default format).
- Keep status and purpose even if not all rows provided a valid status or purpose.
- The hasXxxxOption function in the store are changed accordingly from a 'all' to 'any' reduction. TODO:
- update the doc once we are OK with code.