Changes between 1.10s and 1.10

[Crystalion]

Barbarian double swing cost even less mana than before.  Now, at level 7 it costs 0 mana, at level 13 it costs -1, at level 17 it costs -2

Display error, most likely. A quick SP v1.10 test shows no mana being gained at the -2 level (-act 5 char with pumped double swing; low mana pool therefore slow mana regen; acquire potential melee target; wait for mana regen "pulse"; swing & kill target; observe no mana gain; wait for next pulse; see display updated with only the +1 from the regen pulse).