This commit deprecates the earlier groupname[x-y] syntax in favour of
the inclusive groupname[x:y] syntax. It also makes the subscripting
code simpler and adds explanatory comments.

One problem addressed by the cleanup is that _enumeration_info used to
be called twice, and its results discarded the first time because of the
convoluted control flow.

The possibilities are complicated enough that I didn't want to make
changes without having a complete description of what it actually
accepts/matches. Note that this text documents current behaviour, not
necessarily the behaviour we want. Some of this is undocumented and may
not be intended.

Now everything under _match_one_pattern can ignore them. This also means
that we can use the cache to return the same results for 'foo' and '!foo'.

There are no code changes; this is committed separately so as to make
the subsequent "real" diffs easier to read.

remove defaults from inhertiable fieldattributes to allow for proper detection and override

added block environment test

Speed up execution

`if method in dir(self):` is very inefficient:

- it must construct a list object listing all the object attributes & methods
- it must then perform a O(N) linear scan of that list

Replace it with the idiomatic `if hasattr(self, method):`, which is a
O(1) expected time hash lookup.

Should fix #11981.

fixes #12055

Fixes #12011

cloudstack: more integration tests and updates

Revert "Add PowerShell exception handling and turn on strict mode."

Apart from ansible-vault create, every vault subcommand is happy to deal
with multiple filenames, so we can check that there's at least one, and
make create check separately that there aren't any extra.

Add PowerShell exception handling and turn on strict mode.

draft bsd intro and bootstrapping

made squashable with_ plugin list configurable

Fix a parsing bug that prevents IPv6 addresses from being used with add_host