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/0006-Crop-Growth-Rates.patch

@@ -1,4 +1,4 @@
-From 52b47191f7175fd941117308964a2d01f09f5efe Mon Sep 17 00:00:00 2001
+From 31eb3cc4054b8ca75e9c7a9e87281643fcc7e4ce Mon Sep 17 00:00:00 2001
 From: md_5 <md_5@live.com.au>
 Date: Fri, 21 Jun 2013 17:17:20 +1000
 Subject: [PATCH] Crop Growth Rates
@@ -135,12 +135,12 @@ index 4fae805..a90fab1 100644
  
                  if (l < 7) {
 diff --git a/src/main/java/org/spigotmc/SpigotWorldConfig.java b/src/main/java/org/spigotmc/SpigotWorldConfig.java
-index 478d9e6..f38bb25 100644
+index 6ba7f5c..ddca7c3 100644
 --- a/src/main/java/org/spigotmc/SpigotWorldConfig.java
 +++ b/src/main/java/org/spigotmc/SpigotWorldConfig.java
-@@ -75,4 +75,35 @@ public class SpigotWorldConfig
-         chunksPerTick = getInt( "chunks-per-tick", 650 );
-         log( "Chunks to Grow per Tick: " + chunksPerTick );
+@@ -79,4 +79,35 @@ public class SpigotWorldConfig
+         clearChunksOnTick = getBoolean( "clear-tick-list", false );
+         log( "Clear tick list: " + false );
      }
 +
 +    // Crop growth rates