#221 Taurus4: Docs should be updated

[Carlos Pascual]

The changes from taurus4 should be reflected in the docs:

• Mentions to Configuration should disappear
• model names in examples, etc should be TEP3 compliant
• Tango-centric explanations should be reworded whenever possible
• TEP14 allowed value types should be explained
• A quick Taurus3->Taurus4 migration guide should be written (maybe extend [Taurus4-API_changes] wiki)

(maybe this ticket can be splitted into smaller tickets)

[Carlos Pascual]

Work started in https://github.com/cpascual/taurus/pull/7

The results are automatically built in:
http://www.taurus-scada.org/en/bug-221/

[Zbigniew Reszela]

Review and merged into develop.