GH-1314 add UI for custom minecraft jar addition

Also changes the text of the jar mod addition button.
It should be clearer what it does and hopefully will not confuse
as many people.

application/pages/VersionPage.ui

@@ -7,7 +7,7 @@
     <x>0</x>
     <y>0</y>
     <width>693</width>
-    <height>750</height>
+    <height>788</height>
    </rect>
   </property>
   <layout class="QVBoxLayout" name="verticalLayout">
@@ -206,7 +206,14 @@
             <string>Add a mod into the Minecraft jar file.</string>
            </property>
            <property name="text">
-            <string>Add jar mod</string>
+            <string>Add to Minecraft.jar</string>
+           </property>
+          </widget>
+         </item>
+         <item>
+          <widget class="QPushButton" name="jarBtn">
+           <property name="text">
+            <string>Replace Minecraft.jar</string>
            </property>
           </widget>
          </item>
@@ -281,7 +288,6 @@
   </customwidget>
  </customwidgets>
  <tabstops>
-  <tabstop>tabWidget</tabstop>
   <tabstop>packageView</tabstop>
   <tabstop>changeVersionBtn</tabstop>
   <tabstop>moveUpBtn</tabstop>