Spine takes image name from slot not path (DEF-2709)

[britzl]

Description: Defold seams to use the slot of a image as its path instead of the skins path name.

Steps to reproduce: Create a spine that have a different path than name. Check out the provided zip, the animation json "path" will not work even though the image "logo" is in the atlas provided.

Expected result: The runtime should be able to find the image.

Actual result: The runtime says that the image is missing.

2017-11-29 15:24:12 (Mattias.Hedberg) Attached screenshot of json file. If there is a path entry Defold should use that instead of name.

[JCash]

We use the names reported by the spine loader from the official runtime, and map them to the atlas names in the texture set.