rework ui related scripting stuff

data/modules/mainmenu/ui/mainmenu.otml

@@ -0,0 +1,49 @@
+%panel#background
+  skin: mainMenuBackground
+  anchors.left: parent.left
+  anchors.right: parent.right
+  anchors.top: parent.top
+  anchors.bottom: parent.bottom
+
+  %panel#mainMenu
+    skin: roundedGridPanel
+    size: [117, 171]
+    anchors.left: parent.left
+    anchors.bottom: parent.bottom
+    margin.left: 60
+    margin.bottom: 70
+
+    %button#enterGameButton
+      text: Enter Game
+      anchors.top: parent.top
+      anchors.horizontalCenter: parent.horizontalCenter
+      margin.top: 16
+      onClick: UI.load("entergamewindow")
+
+    %button#accessAccountButton
+      text: Access Account
+      anchors.top: parent.top
+      anchors.horizontalCenter: parent.horizontalCenter
+      margin.top: 46
+      onClick: displayErrorBox("Error", "Not implemented yet")
+
+    %button#optionsButton
+      text: Options
+      anchors.top: parent.top
+      anchors.horizontalCenter: parent.horizontalCenter
+      margin.top: 76
+      onClick: UI.load("optionswindow")
+
+    %button#infoButton
+      text: Info
+      anchors.top: parent.top
+      anchors.horizontalCenter: parent.horizontalCenter
+      margin.top: 106
+      onClick: UI.load("infowindow")
+
+    %button#exitGameButton
+      text: Exit
+      anchors.top: parent.top
+      anchors.horizontalCenter: parent.horizontalCenter
+      margin.top: 136
+      onClick: terminateApplication()