add distutils package classifiers

Handle quoting of values in dict parameters

I was particularly interested in the programming language ones,
but the others might be useful to others browsing PyPI.

Now with GPLv3+, and Utilities topic.

Fixes #10194

A better error message for «ansible playbook.yml»

Fix incorrect example of vars_prompt

Fixes #11746

This is a very conservative change: we add the hint only if we're
definitely going to die already.

Fixes #11470

only set ansible_ssh_host if not already set

functions to do difs.

Add several DNS-related facts by parsing /etc/resolv.conf

Regex escape filter

Facts include nameservers, domain, search path, sortlist, and options.

diff now works with template
also fixed check mode for template and copy

Have ec2.py expand tilde and vars when looking up the EC2_INI_PATH env variable

Fixes #11673

v2 breakage: lookupfile should lookup the given file=xxx

Add more explicit documentation on ansible_nodename and ansible_hostname

Document and test 'is undefined' rather than 'is not defined'

Fix #9971, based on text from Paul Czarkowski

guide_rax.rst: fix add_host invocations

According to https://github.com/ansible/ansible/issues/10273,
this syntax should work better for nested dicts.

(Earlier it used to lookup the pre-split term.)