version bump 0.6.0: windows support

- MakeEncoding.cs program pulls from .NET encodings (tested with Windows 7)
  (outputs stored at dotnet/out and misc/err)
- Many new codepages and improvements
- coverage + coveralls
- better environment handling (h/t @xch89820)
- cpexcel.js for the formats recognized by excel
- decode endian option removed (implicit from codepage definition)
NOTE: utf7 encode can be more space efficient