When checking for Xen for LinuxHardware processor facts, don't check sysfs if already found in /proc/

'vendor_id' and 'model name' keys

Check for Xen paravirt and handle processor facts accordingly

now uses utils.jsonify which does proper utf8 encoding

By default, jsonfile is not documented, and the error message
when fact_caching_connection is not set is a bit puzzling, so
a error message would be beeter ( documentation too ). While redis
is faster for bigger setup, jsonfile is fine for a small setup
and is easier to deploy.

The module will then stop ansible-playbook, as this match better
the philosophy of Ansible being a fail-fast system.

already

Now uses sha1 checksums following merge of 9688.
Also I undid the changes I made to fetch.py
win_template.py now uses conn.shell.has_trailing_slash and
conn.shell.join_path
updated integration tests.

Using the variable name can interfere with various systems
used to communicate between modules and ansible ( as
reported in #7732 , where ansible_facts is a reserved key for
updating the fact cache, for example ).

Fix #9395