Release version 2.3.0

- Recognition of all ISO 639 English names of a language by the Lang class constructor.
- New other_names method to list all the non-reference ISO 639 English names for a given language.
- Minor update of the iso-639-3.tab source file.
- Removed duplicates returned by the individuals method.
- Fixed non-standard public API

setup.py

@@ -5,9 +5,9 @@
 
 setuptools.setup(
     name="iso639-lang",
-    version="2.2.3",
+    version="2.3.0",
     author="L.Beaudoux",
-    description="A lightweight library for the ISO 639 standard.",
+    description="A simple, yet powerful ISO 639 library.",
     long_description=long_description,
     long_description_content_type="text/markdown",
     url="https://github.com/LBeaudoux/iso639",