left align partially hidden widget options

Upon opening a widget menu option, if that option is off the left-hand side of the screen it will now be left aligned (and visible).

This check only occurs when opening a widget option menu. If you were to open a menu and then resize the window, the menu's position will not be updated if the newly resized window forces the menu outside of the screen. @juliusv is this ok, or would you like to have an open menu checked when someone resizes the window?
need to wait for the next event loop to check against the menu element that is being rendered as a result of `toggleTab`.