raise errors when omitted, updated changelog with new modules.

Same doc-typo (confirmed) as https://github.com/ansible/ansible/pull/4759

--remote-user  *should be*  --user

--remote-user= does not work:
 ansible: error: no such option: --remote-user

--user= does. Updating docs

Thi permit to simplify the command line to use by using
a sensible default, and so reduce the number of incorrect
possible choices and setup needed. Among potential
incorrect choices is using a fixed directory in /tmp, which
could be problematic with a setup whose access is not
properly restricted.

If --extra-vars starts with either a '{' or a '[', it will be assumed
we are dealing with JSON and parse the data as such.

document in the man-page that {ansible,ansible-playbook} -M can also be overriden with the ANSIBLE_LIBRARY environment

page.

check path is directory
added manpage & setup
small cleanup
shut up module_formatter in utils to avoid trace print on crud files in library

- added the ANSIBLE_CONFIG environment variable

chapter 3 manpage source does not belong in git because it includes datestamps that constantly change.  Willing to re-add if datestamps
are removable.