Rearrange number casting from lua to java

src/core/org/luaj/vm/LDouble.java

@@ -103,6 +103,14 @@ public class LDouble extends LNumber {
 		return (int) m_value;
 	}
 
+	public long toJavaLong() {
+		return (long) m_value;
+	}
+
+	public float toJavaFloat() {
+		return (float) m_value;
+	}
+
 	public double toJavaDouble() {
 		return m_value;
 	}

src/core/org/luaj/vm/LInteger.java

@@ -58,6 +58,18 @@ public class LInteger extends LNumber {
 		return m_value;
 	}
 	
+	public long toJavaLong() {
+		return m_value;
+	}
+
+	public float toJavaFloat() {
+		return m_value;
+	}
+
+	public double toJavaDouble() {
+		return m_value;
+	}
+	
 	public LString luaAsString() {
 		return LString.valueOf(m_value);
 	}

src/core/org/luaj/vm/LValue.java

@@ -206,22 +206,26 @@ public class LValue {
 	
 	/** Return value as a byte */
 	public byte toJavaByte() {
-		return (byte) toJavaInt();
+		conversionError("number");
+		return 0;
 	}
 
 	/** Return value as a char */
 	public char toJavaChar() {
-		return (char) toJavaInt();
+		conversionError("number");
+		return 0;
 	}
 
 	/** Return value as a double */
 	public double toJavaDouble() {
-		return toJavaInt();
+		conversionError("number");
+		return 0;
 	}
 
 	/** Return value as a float */
 	public float toJavaFloat() {
-		return (float) toJavaDouble();
+		conversionError("number");
+		return 0;
 	}
 
 	/** Return value as an integer */
@@ -232,12 +236,14 @@ public class LValue {
 
 	/** Return value as a long */
 	public long toJavaLong() {
-		return (long) toJavaDouble();
+		conversionError("number");
+		return 0;
 	}
 
 	/** Return value as a double */
 	public short toJavaShort() {
-		return (short) toJavaInt();
+		conversionError("number");
+		return 0;
 	}
 
 	/** Convert to a Boolean value */