Move version command update checking to the implementation

This makes it easier for downstream projects (forks) to replace the
version fetching system with their own. It is as simple as implementing
an interface and overriding the default implementation of
org.bukkit.UnsafeValues#getVersionFetcher()

It also makes it easier for us to organize things like the version
history feature.

Lastly I have updated the paper implementation to check against the site
API rather than against jenkins.

Spigot-API-Patches/Expand-World.spawnParticle-API-and-add-Builder.patch

@@ -10,7 +10,7 @@ This adds a new Builder API which is much friendlier to use.
 
 diff --git a/src/main/java/com/destroystokyo/paper/ParticleBuilder.java b/src/main/java/com/destroystokyo/paper/ParticleBuilder.java
 new file mode 100644
-index 000000000..06f1602f5
+index 00000000..06f1602f
 --- /dev/null
 +++ b/src/main/java/com/destroystokyo/paper/ParticleBuilder.java
 @@ -0,0 +0,0 @@
@@ -493,7 +493,7 @@ index 000000000..06f1602f5
 +    }
 +}
 diff --git a/src/main/java/org/bukkit/Particle.java b/src/main/java/org/bukkit/Particle.java
-index 68cb74420..69aae30a3 100644
+index 68cb7442..69aae30a 100644
 --- a/src/main/java/org/bukkit/Particle.java
 +++ b/src/main/java/org/bukkit/Particle.java
 @@ -0,0 +0,0 @@ public enum Particle {
@@ -515,7 +515,7 @@ index 68cb74420..69aae30a3 100644
       * Options which can be applied to redstone dust particles - a particle
       * color and size.
 diff --git a/src/main/java/org/bukkit/World.java b/src/main/java/org/bukkit/World.java
-index e1e674bab..fbd61137d 100644
+index e1e674ba..fbd61137 100644
 --- a/src/main/java/org/bukkit/World.java
 +++ b/src/main/java/org/bukkit/World.java
 @@ -0,0 +0,0 @@ public interface World extends PluginMessageRecipient, Metadatable {