Revert previous change to clear chunk list on the end of each tick, make it configurable instead.

Whilst the new behaviour was technically correct as it prevented the possibility of the chunk tick list actually increasing over time, it introduced a few issues, namely the fact that it slowed growth to unreasonable levels, and interfered with the values which server admins have finally tuned, and come to enjoy over the last few years.
If it is absolutely essential that growth be halted and ticking reduced as much as possible, the config option is there for power users.
If we wish to 'fix' this by default in the future, a new chunk ticking algorithm, which actually has meaningful config options should be designed.

By: md_5 <git@md-5.net>

CraftBukkit-Patches/0039-Allow-Disabling-of-Random-Lighting-Updates.patch

@@ -1,4 +1,4 @@
-From 3d01e9989ffbcbffe694ef398533b212fa04c11d Mon Sep 17 00:00:00 2001
+From 2155a9e89454ee4120c716bcdc3b744e243ec84b Mon Sep 17 00:00:00 2001
 From: md_5 <md_5@live.com.au>
 Date: Sat, 22 Jun 2013 16:12:02 +1000
 Subject: [PATCH] Allow Disabling of Random Lighting Updates
@@ -31,10 +31,10 @@ index 2cc9005..0b6b681 100644
              entityhuman = (EntityHuman) this.players.get(i);
              j = MathHelper.floor(entityhuman.locX) + this.random.nextInt(11) - 5;
 diff --git a/src/main/java/org/spigotmc/SpigotWorldConfig.java b/src/main/java/org/spigotmc/SpigotWorldConfig.java
-index fc0aa4c..eb118c6 100644
+index 87eac1b..aa639fe 100644
 --- a/src/main/java/org/spigotmc/SpigotWorldConfig.java
 +++ b/src/main/java/org/spigotmc/SpigotWorldConfig.java
-@@ -173,4 +173,11 @@ public class SpigotWorldConfig
+@@ -177,4 +177,11 @@ public class SpigotWorldConfig
          hopperCheck = getInt( "ticks-per.hopper-check", hopperTransfer );
          log( "Hopper Transfer: " + hopperTransfer + " Hopper Check: " + hopperCheck );
      }