Now follows usual behaviour for this kind of zoom.
Still needs to update the comboBox.

after zooming with shift+scroll.
Also now issues full redraws after range is changed.

Double clicking on a channel display in the LFP Viewer maximizes that channel. Double click again or change spread settings to return to normal mode.

Button::setToggleState (bool, bool) was deprecated in favor of
setToggleState (bool, NotificationType).