[RME] Commands' documentation

[acs-l]

Based on #263, this issue aims to define a new way to document commands.

This implementation should :

• Benefit the new commands' declaration to retrieve as much explicit information as it can;
• Infer (i.e.: deduce) unprovided parameters' documentation, based on other parameters which share the same :name and whose method are located under the same :namespace;
• Handle internationalization of documentation's descriptions.
• Supports the description of:
  • deprecated commands (since a given release)
  • see also commands

[acs-l]

Lists of sections (as declared in src/Doc.rb#L631):

• [x] (Acteurs) :actors -> RME::Command::Actors
• [x] (Zones virtuelles) :area -> RME::Command::Area
• [x] (Armures) :armors -> RME::Command::Armors
• [x] (Caméra) :camera -> RME::Command::Camera
• [x] (Presse-papier) :clipboard -> RME::Command::Clipboard
• [x] (Date/Heure) :date -> RME::Command::Date
• [ ] (Ennemis) :enemy -> RME::Command::Enemy
• [ ] (Evénements) :event -> RME::Command::Event
• [ ] (Fichiers) :file -> RME::Command::File
• [ ] (Fenêtre de jeu) :game_window -> RME::Command::GameWindow
• [ ] (En combat) :in_battle -> RME::Command::InBattle
• [ ] (Objets) :items -> RME::Command::Items
• [ ] (Clavier) :keyboard -> RME::Command::Keyboard
• [x] (Carte) :mapinfo -> RME::Command::Map
• [ ] (Mathématiques) :math -> RME::Command::Math
• [ ] (Micro-événéments) :micro -> RME::Command::MicroEvent
• [ ] (Souris) :mouse -> RME::Command::Mouse
• [ ] (Panoramas) :parallax -> RME::Command::Parallax
• [ ] (Equipes) :party -> RME::Command::Party
• [ ] (Images) :picture -> RME::Command::Picture
• [ ] (Sauvegardes) :save -> RME::Command::Save
• [ ] (Scenes) :scene -> RME::Command::Scene
• [ ] (Ecran) :screen -> RME::Command::Screen
• [ ] (Standards) :standard -> RME::Command::Standard
• [ ] (Techniques) :skills -> RME::Command::Skills
• [ ] (Client-Serveur) :socket -> RME::Command::Socket
• [ ] (Sons) :sound -> RME::Command::Sound
• [ ] (Effets spéciaux) :fx -> RME::Command::SpecialEffect
• [ ] (Spritesheet) :spritesheet -> RME::Command::Spritesheet
• [ ] (Systèmes) :system -> RME::Command::System
• [ ] (Textes) :text -> RME::Command::Text
• [ ] (Champs de texte) :textfield -> RME::Command::Textfield
• [ ] (Groupes) :troop -> RME::Command::Troop
• [ ] (Armes) :weapons -> RME::Command::Weapons
• [ ] (Fenêtres) :window -> RME::Command::Window
• [ ] (Vibrations (XBOX360)) :xbox -> RME::Command::Xbox