(bug 46123, hot fix) Activated language terms table would not allow for editing statements

When the language terms table is active, editing/adding of statements is not working since
8f0ec909. This is because that change-set introduced having the second parameter of the
"startItemPageEditMode" event set to a DOM node instead of undefined in case of a
jQuery.wikibase widget would be responsible for triggering the event. In case of
wikibase.ui.PropertyEditTool related ui components triggering the event, a
wikibase.ui.PropertyEditTool.EditableValue would be given as second parameter. Code
expecting a EditableValue failed when after 8f0ec909 a DOM node would be given on statements
related edit interaction.

Change-Id: Ifd908f481f0f671797f2d0ff503fd2125dc9b91d
Merge "(bug 46123, hot fix) Activated language terms table would not allow for editing statements"