Mayhem and Team Mayhem gamemodes

Summary:

New gamemode with Free For All or Team combat. Each player spawns with 200/200 and full ammo like in LMS&CA and pickup items are removed by default, powerups are kept for extra spice but can be removed with whitelisted cvars. Descriptions for the mode based on older gamemodes: "DM had a baby with CA" / "DM without pickups"/"CA without rounds"/"LMS but kills matter instead of lives". Currently no mode has continous fighting with respawning like in (T)DM with starting items except for LMS which is completely about avoiding combat while hiding and letting others fight, in pubs very often the weakest players have to wait minutes before the next game of LMS, at times with certain players even tens of minutes.

Default score logic is a bit different than in DM&TDM. By default weights killing an opponent only gives 25% of a frag and dealing damage worth of full health+armor gives 75% of a frag. These frags are then multiplied by an upscaler to get the score. Default scorelimit is also changed to be 1000 so that gaining score from dealing damage is visible but the default "fraglimit" is 50 for Mayhem and 75 for Team Mayhem. Giving 25% of a frag from a kill gives a reason to still finish off opponents but also doesn't make kills too "delicious" to make killstealing a major problem, especially in FFA Mayhem. A kills only or damage only scoring method is also possible to enable with cvars.

Bugs/TODO:

AFAIK there are no bugs in the mode with its default settings. I don't know how to edit team info in TDM and I copypasted all team based code I found in TDM files and renamed it all to tmayhem, I'd like to have someone test if team stuff actually works before actual merge to master.

As a forwards compatibility issue for outdated clients with older versions than 0.8.5 of the game, they will not see the gamemode icons in server voting screens, this is fixable with having server downloads with a pk3 with proper folder structure to menu themes folders and having mayhem and tmayhem icons included. AFAIK this is the only forwards compatibility feature for gamemode icons and I don't think I'm able to include this pk3 in this branch so that it's automatically activated for server hosts. Only hope is to have people update their old 0.8.2 clients to receive the icons unless every single server hosting admin has a pk3 serverpackage with the icons. This issue will be fixed by the release after 0.8.5 which forces 0.8.2 to update at least to 0.8.5 in order to play on the newest servers.

Player feedback:

I've received positive feedback and love from ~50 players who weren't able to suggest anything improvable or fixable. All eager to have this as an official gamemode. z411 has hosted mayhem on their Chile server and I have not heard any negative feedback from them.

Some players mentioned the mode being "too hectic / chaotic" for their taste while others loved those constant fights without a break. This is H E A V I L Y influenced by the map's layout and size, the amount of players in the map and the playstyle of the players. Bots tend to aggressively group up into a single pile leaving most of the map empty with a single very hot hotspot. As I did most of my early testing in modified category without many human players bots(high skill level ones with modified aim configuration) were present and caused many hotspots. I've yet to have more than 8 good human players to properly test big tdm maps like monstrosity, atelier or bromine which should have more space and therefore less hot hotspots.