functions activity added

res/layout/calc_functions_button.xml

@@ -0,0 +1,14 @@
+<?xml version="1.0" encoding="utf-8"?>
+
+<!--
+  ~ Copyright (c) 2009-2011. Created by serso aka se.solovyev.
+  ~ For more information, please, contact se.solovyev@gmail.com
+  ~ or visit http://se.solovyev.org
+  -->
+
+<org.solovyev.android.view.widgets.DirectionDragButton xmlns:a="http://schemas.android.com/apk/res/android"
+													   a:id="@+id/functionsButton"
+													   a:text="ƒ(x)"
+													   a:textStyle="italic"
+													   a:onClick="functionsButtonClickHandler"
+													   style="?controlButtonStyle"/>