Started creating GuiEditKeyframe

Therefore, added support for floating point numbers in GuiNumberInput

src/main/java/eu/crushedpixel/replaymod/holders/Keyframe.java

@@ -1,9 +1,14 @@
 package eu.crushedpixel.replaymod.holders;
 
-public class Keyframe {
+public class Keyframe implements Cloneable {
 
     private final int realTimestamp;
 
+    @Override
+    public Object clone() {
+        return new Keyframe(realTimestamp);
+    }
+
     public Keyframe(int realTimestamp) {
         this.realTimestamp = realTimestamp;
     }

src/main/java/eu/crushedpixel/replaymod/holders/PositionKeyframe.java

@@ -6,6 +6,11 @@ public class PositionKeyframe extends Keyframe {
 
     private Position position;
 
+    @Override
+    public Object clone() {
+        return new PositionKeyframe(this.getRealTimestamp(), this.getPosition());
+    }
+
     public PositionKeyframe(int realTime, Position position) {
         super(realTime);
         this.position = position;

src/main/java/eu/crushedpixel/replaymod/holders/TimeKeyframe.java

@@ -6,6 +6,11 @@ public class TimeKeyframe extends Keyframe {
 
     private final int timestamp;
 
+    @Override
+    public Object clone() {
+        return new TimeKeyframe(this.getRealTimestamp(), this.getTimestamp());
+    }
+
     public TimeKeyframe(int realTime, int timestamp) {
         super(realTime);
         this.timestamp = timestamp;