Fix ticket 255 - lua error in target.DebuffMeleeCritChance
Fix ticket 255 - lua error in target.DebuffMeleeCritChance

Add default crit chance in case it's missing from the aura.  Make the
default non-zero in case it's used as a divisor in a calculation.

git-svn-id: b2bb544abab4b09d60f88077ac82407cb244c9c9@964 d5049fe3-3747-40f7-a4b5-f36d6801af5f

Xeltor/ovale,ultijlam/ovale,eXhausted/Ovale,ultijlam/ovale,eXhausted/Ovale,ultijlam/ovale,eXhausted/Ovale