* SfxTabDialog constructor has a const pointer parameter
pointing  to the input set and also the corresponding member
is a const pointer which indicated that set is not changed by
the dialog, but this is not true, const is casted away and
the input set is changed.
* So use a copy of the input set instead, pointed by
a non-const member, so we can spare some const cast and
misunderstandings.
* GetRefreshedSet not behaves as a getter method, but changes
the input set instead, so redeclare it accordingly.

Change-Id: Ic63f9ae68c50e65d4498b20f597547c1c075b94e