For editor tooltips and the editor context menu
'Watch expression', always try to find a local variable first
and use its expression.

Change the tooltip manager/widgets not to rely on the debugger
model enum and obscure expression, filter by complete iname
instead. Remove obsolete enumeration.

Change gdb's handling of tooltips such that local variables
are displayed immediately without creating additional tooltip
items.

Change-Id: I9b55823428029ba50d84d3a8cab55eb58942e72b
Reviewed-by: hjk <qthjk@ovi.com>