fix for bug #368661: on running the installer, remove the updates directory, updates.xml and active-update.xml files. otherwise, we could have a pave over install that then applies a pending update. additonally, after a pave over install the update history needs to be reset.

r=mscott, rstrong

mail/installer/windows/nsis/installer.nsi

@@ -286,6 +286,10 @@ Section "-Application" Section1
   ${DeleteFile} "$INSTDIR\install_wizard.log"
   ${DeleteFile} "$INSTDIR\install_status.log"
 
+  RmDir /r "$INSTDIR\updates"
+  ${DeleteFile} "$INSTDIR\updates.xml"
+  ${DeleteFile} "$INSTDIR\active-update.xml"
+
   SetDetailsPrint textonly
   DetailPrint $(STATUS_INSTALL_APP)
   SetDetailsPrint none