Increase lvl range from 10 lvls to 15 lvls

[azurerogue]

Everyone always complains about 1 INT Bragi. But it's really not that bad.
1 INT + Level 10 Bragi + Level 10 Music Lessons = -70% cast delay
100 INT + Level 10 Bragi + Level 10 Music Lessons = -90% cast delay

I'm not arguing that stacking INT isn't efficient, but given the fact that most parties on heRO aren't built to min/max the difference really isn't the end of the world.