CommandApduTest: Also check getNe()
CommandApduTest: Add some Ne edge cases

The extended form ones with Ne >= 32768 fail.
Iso7816LibTests: Add some getNe() edge cases

The extended form ones with Ne >= 32768 fail.
Iso7816Lib.getNe(): Fix return value for Ne >= 32768

A negative value would be returned in this case.
Merge pull request #7 from weinhold/fix-getne

Fix Iso7816Lib.getNe() -- handling of values >= 32768