Removes unused menu and strings.

Remove code for starting to create (the wrong way) a popup menu.
Adds dialog fragment for player list.

Adds the initial fragment to be used to display the player list for
picking which player to substitute in.
Switches openSubList to use the PlayerListFragment

Removes code to create a ListPopupWindow in response to clicking the
button and replaces it with creating a PlayerListFragment and showing
it.