Wordlist new XML properties for gletters & wordsgame

- Wordlist levels have 3 new, optional parameters:
-- fallspeed: how fast the words fall
-- speed: how fast a new item is dropped after the last one
-- sublevels: how many items are in the level

- gletters:
-- use the new parameters
-- display bonus at end of level

- wordsgame:
-- use the new parameters
-- display bonus at end of level
-- levels now start with a defined speed + fallspeed
   when the user clicks through the levels