Fix dependency specification of typing_extensions

All prior releases have been broken when using pip install

This release has been tested in a virutalenv (the first one too sucessfuly do so).

Explicitly declare support for python 3.9

This is the first version that correctly supports python 3.9.

Features

Explicitly declare support for python 3.9 using requires-python field.

Fixes

Fixes an import error with TypeAlias in Python 3.9, which was not part of the stdlib typing module. Instead, import it from typing_extensions which contains a backport.

Initial release

Simple glob group expansion `foo{bar,baz}" -> ["foobar,", "foobaz"]

Relies on funcparserlib for parsing.

Design and API mirrors my rust library