Added xml for GraphPad Prism per RT247056

packages/prism.xml

+<?xml version="1.0" encoding="UTF-8"?>
+<packages:packages xmlns:packages="http://www.wpkg.org/packages">
+  <package id="prism" name="GraphPad Prism" revision="%version%.1" priority="0" reboot="false">
+
+    <variable name="version" value="10.4.1.627" />
+    <!--Taken from searchreg.vbs DisplayName. N.B. different than DisplayVersion-->	  
+
+    <check type="uninstall" condition="exists" path="GraphPad Prism %version%" />
+
+    <install cmd='msiexec /qn /i %WPKGSOFTWARE%\prism\InstallPrism10.msi' />
+    
+    <upgrade include='remove' />
+    <upgrade include='install' />
+
+    <remove cmd='msiexec /qn /x{933C02B4-14E6-4601-9CEA-5E22E80030C6}' />
+
+  </package>
+</packages:packages>
+