Update Notes for v0.98

Activated the Campaign Editor: It is now possible to create and share your own single-player campaigns
Campaign Selector: It is now possible to subscribe to campaigns made by other players
AI players are now supported in online games (with adjustable latency, balancing between smoothness and reaction times)
Dedicated server admins can upload their AI groups and lines (subscribed ones and the ones belonging to a share group) at session init
Added option Force AI Supported Levels to hosts - changes the level is there are not enough players and the next level does not support AI
Added automatic vehicle changing rules to hosts - changes the vehicle automatically based on the next level's level list (tags)
It is now possible to make the experimental physics settings not affect the AI controlled vehicles
Level Editor: Added new terrain textures
Level Editor: Curb, Kart barrier and flat building colors can now be changed
Level Editor: Added new house models (with changeable styles, check the Level Colors window)
Customizer: The previously selected paint texture is now initially shown and selected in the texture picker window
Campaigns: Event result tooltip now shows requirements for all levels
Sumo: It is now possible to make the last contacts in a sumo level never expire (a setting in the level properties)
Leaderboards: Left-clicking Play against ghost button now keeps the multi-selected ones, too
Damage Settings: If Health After Respawning is below 100%, there is an extra option Respawn Never Decreases Health
Capture Battle: Wrecked players no longer can capture a flag (fixed losing and recapturing it in a loop)
Steam SDK version updated - Linux server admins may need to run .steam/steamcmd/steamcmd.sh once if steamclient.so is not updated
Miscellaneous other minor fixes and improvements