Fixes with latest Spine examples

[gutomaia]

Hi there,

I'm trying to use pyguts with some latest spine examples, and most of them fails in the same way, I've created a branch with most of them at:

https://github.com/gutomaia/pygame_spine_examples/tree/latest_spine_examples

I'm trying to fix them and send a PR, although, any help is welcome.

The following StackTrace is the most common error:

  File "/home/gutomaia/projetos/games/spineproto/spine_examples/base.py", line 32, in __init__
    self.skeleton = spine.Skeleton(skeletonData=self.get_skeleton_data())
  File "/home/gutomaia/projetos/games/spineproto/spine_examples/base.py", line 27, in get_skeleton_data
    cls.__skeleton_data = skeleton_data(atlas_file, skeleton_file)
  File "/home/gutomaia/projetos/games/spineproto/spine_examples/base.py", line 16, in skeleton_data
    return skeletonJson.readSkeletonDataFile(skeleton_file)
  File "/home/gutomaia/projetos/games/spineproto/venv/local/lib/python2.7/site-packages/spine/SkeletonJson.py", line 49, in readSkeletonDataFile
    return self.readSkeletonData(jsonPayload=jsonPayload)
  File "/home/gutomaia/projetos/games/spineproto/venv/local/lib/python2.7/site-packages/spine/SkeletonJson.py", line 127, in readSkeletonData
    attachmentMap.get('name', attachmentName))
  File "/home/gutomaia/projetos/games/spineproto/venv/local/lib/python2.7/site-packages/pyguts/AtlasAttachmentLoader.py", line 14, in newAttachment
    return RegionAttachment.RegionAttachment(region)
  File "/home/gutomaia/projetos/games/spineproto/venv/local/lib/python2.7/site-packages/pyguts/RegionAttachment.py", line 34, in __init__
    self.texture = region.page.texture.subsurface(self.rect)
ValueError: subsurface rectangle outside surface area