Enhance error message about missing ControlPersist

ansible_ssh_args is good for playbook, but in the ~/.ansible.cfg
file, it should be ssh_args in a specific section.
Clean a bit more the ssh_args configuration

If someone add ssh_args = " " to his .ansible.cfg, it will result into
strange failure later :

    <server.example.org> ESTABLISH CONNECTION FOR USER: misc
    <server.example.org> REMOTE_MODULE ping
    <server.example.org> EXEC ['ssh', '-C', '-tt', '-q', ' ', '-o', 'KbdInteractiveAuthentication=no',
    '-o', 'PreferredAuthentications=gssapi-with-mic,gssapi-keyex,hostbased,publickey', '-o', 'PasswordAuthentication=no',
    '-o', 'ConnectTimeout=10', 'server.example.org', "/bin/sh -c 'mkdir -p /tmp/ansible-tmp-1397947711.21-5932460998838
    && chmod a+rx /tmp/ansible-tmp-1397947711.21-5932460998838 && echo /tmp/ansible-tmp-1397947711.21-5932460998838'"]
    server.example.org | FAILED => SSH encountered an unknown error during the connection. We recommend you re-run the
    command using -vvvv, which will enable SSH debugging output to help diagnose the issue

The root cause is the empty string between -q and -o, who kinda break mkdir.
fixed ETIME issue on FreeBSD 8 through 10, which broke all fact
gathering
Improve error message when multiple action are given

This can be illustrated using this playbook:

    - command: id
      delegate_to: "{{ remote_server }}"
      user: "{{ remote_user }}"

The error is to use 'user' instead of 'remote_user', but the error message
do not really mention it, so it can be a bit hard to spot.
Add an example to show all hostvars using debug

This is a useful example to help debug how facts and vars are being collated.
Explicit check of return code for autoinstallation of python-apt added

This will allow easier debugging through more meaningful error message.
Merge pull request #7081 from bcoca/freebsd_fact_fix

fixed ETIME issue on FreeBSD 8 through 10, which broke fact gather
Prevention for catching unrelated exceptions added
Small bug - 'acts' should be 'facts'
Merge pull request #7078 from mscherer/fix_error_message_controlpersist

Enhance error message about missing ControlPersist
Merge pull request #7079 from mscherer/fix_error_whitespace_in_config

Clean a bit more the ssh_args configuration
Merge pull request #7082 from bcoca/freebsd_mtu_fix

fixed issue with FreeBSD network facts
Merge pull request #7083 from mscherer/better_message_multiple_action

Improve error message when multiple action are given
Properly catch and decode unicode strings in module _log_invocation()

Fixes #7084
Merge pull request #7094 from radeksimko/apt-autoinstall-fix

Add check of return code for autoinstallation of python-apt
Merge pull request #7095 from radeksimko/pokemon-exc-fix

Prevent catching unrelated exceptions
Merge pull request #7096 from CaptTofu/docker

Small bug - 'acts' should be 'facts'
Merge pull request #7089 from dagwieers/debug-docs

Add an example to show all hostvars using debug
Update facts.py

Fixes #7093 --devel
Merge pull request #7099 from faust64/patch-2

Update facts.py