fixed skeletons setAttachment using getAttachment

getAttachment does not exist, now uses getAttachmentBySlotIndex
fixed boundingbox typo

BoundingBox was boundingbox and boundingBox different places, now it is
boundingBox everywhere
Revert "fixed boundingbox typo"

This reverts commit 2715e2409fd2db16ffa1e05e57cf0fdb48c1c0a7.
attachment type bounding box should be lower case

Fixed all occurences of spine.AttachmentType.boundingBox to be
lowercase.
Merge remote-tracking branch 'upstream/master'
Merge pull request #216 from smaren/master

Fixed instances of AttachmentType.boundingbox to be lowercase everywhere