Avoid reopening the serial monitor during upload

avoidMultipleOperations becomes false with a 10 seconds timeout after pressing the compile button.

The new code introduced by 99f6043 didn't take this into account, so the port was being reopened before staring the actual upload.

Also, make uploading variable static to avoid preferences confusion (this should be solved in a saner way giving every Editor instance its own set of properties, but it will hopefully fixes by the cli integration and workspace concept)

app/src/processing/app/AbstractMonitor.java

@@ -85,7 +85,7 @@ public void actionPerformed(ActionEvent ae) {
               suspend();
             }
           } else {
-            if (closed && (Editor.avoidMultipleOperations == false)) {
+            if (closed && (Editor.isUploading() == false)) {
               resume(boardPort);
             }
           }

app/src/processing/app/Editor.java

@@ -219,7 +219,7 @@ public boolean test(SketchController controller) {
   private JMenuItem saveAsMenuItem;
 
   //boolean presenting;
-  private boolean uploading;
+  static private boolean uploading;
 
   // undo fellers
   private JMenuItem undoItem;
@@ -2110,6 +2110,10 @@ public void run() {
     }
   }
 
+  static public boolean isUploading() {
+    return uploading;
+  }
+
   private void resumeOrCloseSerialMonitor() {
     // Return the serial monitor window to its initial state
     if (serialMonitor != null) {