ttools: add missing getLongArrayProperty method to JELRowReader

The absence of this method meant that JEL expressions attempting to
subscript long arrays failed.  I'm 95% sure that its omission in
the first place was just an oversight rather than for some subtle
JEL reason.

topcat/src/docs/sun253.xml

@@ -18240,6 +18240,8 @@ introduced since the last version:
             in multi-SIA/SSA windows.</li>
         <li>URL selector fields in Activation Action window are now
             editable.</li>
+        <li>Fix bug which prevented access to long integer array elements
+            from expression language.</li>
         </ul>
         </p></dd>
 

ttools/src/docs/sun256.xml

@@ -8422,6 +8422,8 @@ eds. C. Gabriel et al., ASP Conf. Ser. 351, p. 666 (2006)
         <li>Add some more colour maps.</li>
         <li>Fix some broken and misdocumented non-table-output JyStilts
             commands (<code>tcube</code>, <code>pixfoot</code>).</li>
+        <li>Fix bug which prevented access to long integer array elements
+            from expression language.</li>
         </ul>
         </p></dd>
     </dl>

ttools/src/main/uk/ac/starlink/ttools/jel/JELRowReader.java

@@ -683,6 +683,11 @@ public int[] getIntArrayProperty( int id ) {
              ? (int[]) getObjectColumnValue( id )
              : (int[]) getConstantValue( -1 - id );
     }
+    public long[] getLongArrayProperty( int id ) {
+        return id >= 0
+             ? (long[]) getObjectColumnValue( id )
+             : (long[]) getConstantValue( -1 -id );
+    }
     public float[] getFloatArrayProperty( int id ) {
         return id >= 0
              ? (float[]) getObjectColumnValue( id )