Custom Background Music

[](https://discord.gg/ykHRhmC)  Provides a framework for [custom background music](https://github.com/FirEmerald/CustomBGM/wiki/Background-Music-Providers) to be used by both mods and map makers. Also adds support for [custom loop points in sounds](https://github.com/FirEmerald/CustomBGM/wiki/Adding-Loop-Points-to-Sounds). The BGM block can be used to set the BGM for a specific bounding area The Boss Spawner block is a helper block that can be used to spawn an enemy and play a specific BGM while the entity is alive. * the entity will be despawned and the block reset if a player leaves the activation area * the block is only active while powered by redstone * the block will output a comparator strength of 7 when the boss is spawned and 15 when it is killed * turning the redstone signal off resets the block so it can be used again The Entity Tester block is a helper block to test for entities inside a bounding area