New TurnKey Ansible version (16.1)

Update Ansible to latest 2.x upstream version - 2.10.7. (Note v3.0 has been released very recently. However, there is little documentation our appliance will ship with v2.x for this release).
Include Anisble-Semaphore - a 3rd party Ansible web UI. Currently installed via upsream deb. Includes latest Semaphore - v2.6.8. Closes #1366.
Previous TurnKey landing page (aka tklweb-cp) removed (browsing to appliance defaults to Semaphore now).
Note: Please refer to turnkey-core's 16.1 changelog for changes common to all appliances. Here we only describe changes specific to this appliance.