read-flight ignores IGC hemispheres

[twpayne]

The IGC reader in read-flight.ts ignores the latitude and longitude hemispheres in IGC B records, with obvious consequences.

[Turbo87]

@twpayne thanks for reporting this. the implementation in read-flight.ts was just a quick prototype to allow me to iterate on the scoring code. by now I've extracted a more full-featured IGC file parser into https://github.com/Turbo87/igc-parser and will reuse that from now on. obviously that one works with southern and western coordinates too now 😉