Fix Northeast abbreviation
Add the ability to initialize with the heading abbreviation as an alternative to the heading in degrees
Update readme
Update readme with American spelling
Merge pull request #1 from metabren/enhancements

Fix Northeast abbreviation and Allow init with abbreviations (instead of only degrees)
Merge branch 'master' of https://github.com/flightblog/ZFCardinalDirection
Merge branch 'master' into dev
adding simple 8 pt headings in english