Game balance changes, more of everything
Added very basic mod support, the ECSMod class is still hardcoded in the JavaMod loader.
Renamed Mods to ModLoader.
Unignore test resources in cardshifter-core.
Renamed com.cardshifter.core.mod to com.cardshifter.core.modloader.
Refactored the modloader to implement an interface and offer a default directory-based modloader.
Converted 4 spaces to tabs.
Refactored the modloader to support unloading mods, but mod unloading is not supported yet in the concrete implementations.
Made the constructors of all mod implementations package-private.
Ignoring a test because of several changes to game cards
Entities with attack <= 0 can no longer attack
Added concrete implementations of unloading mods, basic mod support is finished now, closes #44.
Fixed trample damage when attacking. Fixes #46
Added `Resources.getOrDefault` utility method
Made Trample as an ability/resource instead of all entities having it
Invites are now removed when game starts or it is rejected. Fixes #73
Added requirement that the Path argument of the DirectoryModLoader must be a directory.
Added requirement that the Path argument of ModLoaderHelper.getConfiguration must be a directory.
Added feature to create mods at runtime in the test code, and implemented a test with a simple mod to verify that it works.
Merge branch 'ecs-module-support' into develop