Log Message:
Update comms/py-gammu to py-gammu-2.3.
ok wiz@

pkgsrc changes:
* No longer use Makefile.common now that py-gammu is released as a separate
  package by upstream too.

Changes:
2.3
===
* License changed tp GPL version 2 or later.
* Documentation improvements.

2.2
===
* Documentation improvements.
* Code cleanups.

2.1
===
* Include data required for tests in tarball.
* Include NEWS.rst in tarball.
* Fixed possible crash when changing debug file.
* Fixed various errors found by coverity.

2.0
===
* Separate Python module.
* Compiles using distutils.
* Support Python 3.