Update codebase to C++14

Created by: stephanemagnenat

The current Aseba codebase is mostly C++03. Recently, Aseba has been switched to C++14, and new code is expected to use the new C++14 features. Progressively, existing code should be migrated.

The following features should be used:

• override: methods that override parent ones should explicitly state that through the override keyword.
• noexcept: functions that are guaranteed not to return exception should state that through the noexcept keyword.
• constexpr: objects and functions that can be const expressions should state that through the constexpr keyword.
• autogenm: in interfaces with virtual destructors, when not manually specified, the following auto-generated members should be specified as default: copy constructor, copy assignment operator, move constructor, move assignment operator.
• defval: when it makes sense, class members should be given default values to simplify the constructors.
• usingalias: instead of typedef, keyword using should be for template aliasing.
• enum: use strongly-typed enums whenever meaningful.
• nullptr: use nullptr whenever a NULL pointer is used.
• auto: use auto and range-based loops whenever it makes sense.
• contstit: use const_iterator whenever possible, using cbegin() and cend().
• array: use std::array instead of C arrays.
• passbyvalue: when a constructor copies a variable into its own, pass by value and std::move.

The following code parts of Aseba must be updated:

• common/
• compiler/
• transport/dashel_plugins
• clients/studio
• clients/thymioupgrader
• clients/thymiownetconfig
• other tools in clients/
• switches
• targets
• examples