I18N help messages.
Adds HelpMessage.
Adds HelpSequence and creates helps messages for some views.
MockupViews displays a HelpSequence when setting a view.
Adds PositionedHiddenPanel.
Refactoring for IconWithPanel. SwarchWidget, HiddenPanel and PrefabPanel fixes.
Merge pull request #730 from RotaruDan/cameraView

Adds HelpMessage management to eAdventure Mockup.
WIP