removed unused require from Skeleton.lua
rewrote self:setAttachment to use findSlot rather than linearly searching for slotName
fixed crash (syntax error)
fixed animation bugs related to tracks by iterating with pairs rather than keeping track of the trackCount variable by hand.
removed unused function linearSearch
fixed a bug in self:apply() -- # does not count the 0th index
SkeletonJson.lua had "execute" permission