Consist support for X/Backspace/Delete keys for deletion operations

Builds upon consistent key handling support established by previous commits.

Author: EdNutting

src/com/modsim/gui/view/ViewUtil.java

@@ -410,7 +410,9 @@ public void keyPressed(KeyEvent e) {
             }
         }
         // Delete selection
-        else if (e.getKeyCode() == KeyEvent.VK_DELETE
+        else if ((   e.getKeyCode() == KeyEvent.VK_DELETE
+                  || e.getKeyCode() == KeyEvent.VK_BACK_SPACE
+                  || e.getKeyCode() == KeyEvent.VK_X)
                  && !Main.selection.isEmpty()) {
             Main.selection.deleteAll();
         }

src/com/modsim/tools/EditLinkTool.java

@@ -136,6 +136,8 @@ public BaseTool lbUp(int x, int y) {
     public BaseTool keyDown(int key) {
         switch (key) {
             case KeyEvent.VK_X:
+            case KeyEvent.VK_DELETE:
+            case KeyEvent.VK_BACK_SPACE:
                 Main.opStack.cancelCompoundOp();
                 link.highlight = false;
                 link.delete();

src/com/modsim/tools/MakeLinkTool.java

@@ -68,7 +68,9 @@ public BaseTool mouseDrag(int x, int y) {
 
 	@Override
 	public BaseTool keyDown(int key) {
-		if (key == KeyEvent.VK_BACK_SPACE) {
+		if (   key == KeyEvent.VK_BACK_SPACE
+            || key == KeyEvent.VK_DELETE
+            || key == KeyEvent.VK_X) {
 			if (curve.removePt()) 	return this;
 			else 					return null;
 		}