Fix various broken sample functionality - add ability to create a wxAuiNotebook back.
Minor sample clarity fix.
Remove 'all panes' menu item that wasn't doing anything.
Remove the "use x as content pane" menu items that aren't doing anything currently.
Start toying with some initial menu items to alter pane state Hide/Dock etc.
What would be ideal is if we could use this menu to both show and alter almost all properties for the currently active pane.
Merge pull request #67 from mjmacleod/aui-dynamic-notebook

Sample updates
Merge branch 'aui-dynamic-notebook' of https://github.com/nhold/wxWidgets into aui-dynamic-notebook