Formerly the GMM, AGI and SCI duplicated the logic for USE_SAVEGAME_TIMESTAMP.
Now I added a method to SaveLoadChooser instead, which takes care of this. This
might not be the best placement of such a functionality, thus I added a TODO
which talks about moving it to a better place.
This reduces the code duplication in all client code, which formerly duplicated
the querying of the plugin, game id etc. and now simply calls the newly added
method runModalWithCurrentTarget() on a SaveLoadChooser object.
We already pass the title and process button name to the constructor of
SaveLoadChooser and then do not offer any way of changing it, thus changing
the edit mode of the chooser is kind of pointless and was never actually used.
Instead we pass the mode on SaveLoadChooser construction now.
This removes the dependency on array.h from str.h.
Also, begun migration from the confusing type name "StringList" to
the more appropriate StringArray.
svn-id: r48282
