Removing focus from hidden windows upon hiding them.
Setting dialog titles in Title Case.
Setting menu titles in Title Case.
Upon toggling off a window, now attempting to focus SongEditor, then any other visible editors, or finally the parent window if all editors are hidden.
Merge pull request #1414 from csimons/dialog-titles

Adopt "Title Case" for dialog titles and menu text.
Merge pull request #1406 from csimons/unbind-keys

Removing focus from child windows upon hiding them.