see commit 836d9864

ISCHECKFORPRODUCTUPDATES is a de-facto standard for enabling or
disabling Online Update feature. We had this property but it was
unused for a long time. Now LibreOffice can be installed with
msiexec /i LibO<version>.msi ISCHECKFORPRODUCTUPDATES=0 in order
to disable Online Update feature.

"PangoAttrIterator * pango_attr_list_get_iterator (PangoAttrList *list);

Returns : the newly allocated PangoAttrIterator, which should be freed with
pango_attr_iterator_destroy()."

and ClickLightHdl always takes a non-NULL argument, so NULL test is
pointless. Turn it into a normal method that takes a reference.
GetLightSource can be const. Nothing calls DoubleClickHdl, remove it.

This a a prep-work for if and when we use gerrit
it is very important to call gerrit's commit-msg hook
and the sooner we teach our own hook to play nice with it
the less likely we will have issue during migration

This reverts commit 4001370b.

Conflicts:

	unusedcode.easy