Add tabs to file manager

src/filemanager.ui

@@ -16,7 +16,7 @@
   <widget class="QWidget" name="centralwidget">
    <layout class="QHBoxLayout" name="horizontalLayout">
     <item>
-     <layout class="QVBoxLayout" name="verticalLayout">
+     <layout class="QVBoxLayout" name="leftLayout">
       <item>
        <widget class="QLineEdit" name="leftPath">
         <property name="readOnly">
@@ -30,7 +30,7 @@
      </layout>
     </item>
     <item>
-     <layout class="QVBoxLayout" name="verticalLayout_2">
+     <layout class="QVBoxLayout" name="rightLayout">
       <item>
        <widget class="QLineEdit" name="rightPath">
         <property name="readOnly">
@@ -60,6 +60,7 @@
     </property>
     <addaction name="actionLoad_FITS_keywordsLeft"/>
     <addaction name="actionSelect_columnsLeft"/>
+    <addaction name="separator"/>
    </widget>
    <widget class="QMenu" name="menuRight_Tab">
     <property name="title">
@@ -67,6 +68,7 @@
     </property>
     <addaction name="actionLoad_FITS_keywordsRight"/>
     <addaction name="actionSelect_columnsRight"/>
+    <addaction name="separator"/>
    </widget>
    <addaction name="menuLeft_Tab"/>
    <addaction name="menuRight_Tab"/>