[Playtest] Enabled campaign missions, disabled skirmish missions

[Campaign] Implemented the character fatigue system
[Campaign] Implemented the "Rest" perk
[Campaign] Implemented the "Restless" skill

[Game] Fixed the fit to screen feature not taking resting spots into account when the whole squad is resting

[UI] Restored the path aiming icons, made the target lines more visible
[UI] Added some offset to the overlapping timeline action icons
[UI] Now open the aiming menu by right clicking on the aiming target marker
[UI] Now open the grenade menu by right clicking on the grenade target marker
[UI] Now close the character/door/grenade/aiming menus by clicking outside the menu
[UI] Added tooltips explaining how the weapon and skill points work
[UI] Improved the skill panel colors
[UI] Fixed the skill points diamond sprite resolution

[Audio] Stop the background music when entering the map editor