Before this this commit the terminal strip editor couldn't only work on
the first project opened into this editor, all other project opened
after couldn't be edited.
This is now past, terminal strip editor can now edit every project open
in QElectroTech.
Since this commit, the terminals can't be moved from the tree widget,
instead we need to use the "move in" widget to move one or several
selected terminals in the table view.
TerminalStripTreeDockWidget::on_m_tree_view_currentItemChanged
call setCurrentStrip only when current strip changed, and not every time
when user click in another item on the tree view.
