As widgets are added and deleted from the tab widget, they can end
up in almost any order. As a result, when the window is raised, the
current tab does not necessarily reflect an item currently in the
watch view. Instead, make a tab the current one as it is added,
ensuring one of the currently relevant values is displayed by default.

Change-Id: Ia2d2eb60c844a008f8086820564dd20389ce519b
Reviewed-by: hjk <qthjk@ovi.com>