Tidying up

Using extension Selector instead of Navigator
Added ToolNavigPageAdd and ToolNavigPageRemove methods to App::Codit
Plugin PodViewer keeps the view intact after reload
Plugin Sessions takes a pause between opening and closing files
Plugin PodViewer now refreshes when selected
Plugin Console takes focus when selected and gives the text widget focus when unselected
Fixed opening files in unique mode
Running macros show a progress bar
Plugin Git loads projects in a non blocking manner and shows a progress bar