Divide main window controller into several controllers

Author: introfog

src/main/java/com/github/introfog/gitwave/controller/ExecuteController.java

@@ -0,0 +1,9 @@
+package com.github.introfog.gitwave.controller;
+
+import com.github.introfog.gitwave.model.StageFactory.FxmlStageHolder;
+
+public abstract class SupportController extends BaseController {
+    public SupportController(FxmlStageHolder fxmlStageHolder) {
+        initialize(fxmlStageHolder);
+    }
+}