Patch 1.31 'Songs from the Front' feature

Music
* All main menu music has been replace with custom made goodies. They are not final, we are working on some improvements to them.
* Added some temporary win/lose music for Soviets. These will be changed in the future.

Balance Changes
* Increased Katyusha's population to 6.
* Increased Katyusha's cost by 50mp.
* RMC starting unit has been changed to Marine Sappers. These starting Marine Sappers are special however, having increased health over the normal Marine Sappers.
* While using RMC, commandos from the Royal Commandos tree can no longer build trenches.
* While using RMC, and selecting the Royal Engineers tree upgrade 'Improved emplacements', trenches can be built by the Sappers only.
* SAS Raiders population increased to 8.
* Achilles reload time changed to slightly increased.
* Decreased Achilles damage against buildings.
* Increase RMC Lieutenant health by about 15%.
* Increase RMC Captain health by about 15%.
* Decreased the range of ZiS support guns.
* Increased the cost of ZiS support guns to 300 manpower unupgraded and 320 manpower upgraded.
* ISU-152 barrage cooldown doubled. Also added a cost per use at 40 munitions.
* ISU-152 can no longer fire immediately after its barrage ability has been used.
* ISU-152 damaged attuned to a more reasonable level.
* Command squad global vet bonus per level reduced from 10% to 7% per level. Vet requirement increased by 1/2/4 xp.
* Soviet Sniper Team adjustments:
- Enemy snipers will automatically target the Sharpshooter over the Observer, unless specified to do otherwise.
- Decreased population to 3.
- Armor type changed to 'infantry_sniper' on the sharpshooter.
- Decreased health on the observer.
- Sharpshooters gun adjusted to fire slower.
- Observer's chance for critical reduced from 20% to 10%.
* PTRD damage against all infantry massively reduced.
* Soviets can now drop DP-28.
* Assault Grenades now have the potential to kill units.
* Blitz Tiger CP has been increased by 1.
* Tank Riders can now capture points while mounted on a tank.
* Tuned Command Squad's PPS-43's to be more effective in close range, and less effective at longer ranges.
* RMC's Comet Tank no longer requires CCT to be built.
* Recrewing none-upgraded Soviet AT-Guns will no longer give abnormal behavior.
* T90 amd T70 armour type changed to 'Stuart'
* All types of T34s now accelerate and decelerate slightly faster.

Bug Fixes
* Conscripts no longer 'charge' the enemy.
* Fixed while using RMC, HQ call-in would not have access to all units.
* Penal Troops can now no longer be suppressed.
* Partisans no longer lose their booby trap ability when a Medic Truck is built.
* Blitz Tiger and Reward Tiger now have firing sounds.
* Bergetiger's model is no longer messed up.
* Wrecks of all Tiger types are no longer messed up.
* Fixed that Marine Engineers didn't have retreat to Captain ability.
* Fixed a bug where Tank Hunters couldn't recrew heavy weapons.
* Fixed so you won't get both Support and Recon Jeeps when you double click one of them.
* Fixed hotkey for RMC Support Jeeps.
* Fixed vanilla issue StuG IV's shooting, where the shot came out below the main gun.
* Fixed visual issue with DP-28's, where they would appear as Bren Guns on lower graphic settings.
* Soviet units should no longer reference them self as British or American units in their speeches.
* Fixed a bug where US players sometimes received less resources then expected.
* Katyusha's can no longer longer crush infantry.
* Katyusha's can drive though heavy objects (walls, tank traps etc).
* ZiS-5 can no longer longer crush infantry.
* ZiS-5 can drive though heavy objects (walls, tank traps etc).

Art
* M36 Jackson removed in favor of a new M10 model, which doesn't have the misfire bug. Model by Eliw00d and DMz.
* New Model for all ZiS Support Guns.
* Did minor art changes with the following skins: Jagdtiger, PPSh-41 and Mosin-Nagant.
* Fixed ISU-152 mini-map symbol.
* Minor bug fixes on multiple Infantry Models (such as the eyes on Tank Hunters)
* Other races then Soviets, no longer have the Soviet Mortar Weapon Crew portrait when recrewing a Soviet Mortar.
* Tuned the color of SVT-40 to look more realistic.
* Inspiring Speech is now using a custom icon above head instead of the Blitzkrieg one.
* Molotov Cocktail now has a proper model and skin.

Maps
* Sector layout from Vienna has been redrawn.
* Added new weather settings to Vienna.
* Map design has been slightly optimized on Vienna.
* Sector layout from Cottbus has been redrawn.
* Added new weather settings to Cottbus.
* Map design has been slightly optimized on Cottbus.
* Sector layout from Kursk has been redrawn.
* Added new weather settings to Kursk.
* Sector layout from Sevastopol has been redrawn.
* Performance on Sevastopol has been slightly improved.

Localisation
* Updated Polish translation.