2.0 Release

[declension]

• [x] Add basic MQTT HOWTO
• [x] Branch 1.x for any parallel dev (though aim to minimise this, life is short etc) from last tag.
• [x] Cherrypick non-specific recent changes to 1.x
• [x] Add deprecation note there
• [x] Add French support
• [x] Update translation information
• [x] Prepare mqtt-squeeze docs / CLI
• [x] Assemble files and create release & tag