Add a stack window menu entry to display QML stack frame.

Add language field to stack frame.
Add virtual for loading QML stack invoked by stack window
context menu, implement for CDB, GDB.

Task-number: QTCREATORBUG-11144

Change-Id: Ic39be3978b40d96ed18cb69a8355296ec572ece7
Reviewed-by: hjk <hjk121@nokiamail.com>
Unify text on buttons that open the options dialog

We have many buttons that open the options dialog, and many of these use
different terms.

Change-Id: I073fe2a23569c6f4174a2fb6567359c89cb2427c
Reviewed-by: hjk <hjk121@nokiamail.com>
Reviewed-by: Leena Miettinen <riitta-leena.miettinen@digia.com>