Prepare for release 2.22

fixes #522

Update TODO to mention bdist_wheel

Update instructions to release. Release 2.20 was pushed

Bump versions to 2.19

Update version number to 2.18 for release

Merge branch 'master' of github.com:eliben/pycparser into try-release…

…-2.17

Conflicts:
	TODO.txt

Prepare 2.16 for release

Prepare for releasing v2.15

Preparing for release 2.14

Update version and CHANGES for 2.13 release