Allow existing nine-patch images for editing

[GoogleCodeExporter]

What steps will reproduce the problem?
When I add an existing 9patch image, it redraws dots to the exterior. 

What is the expected output? What do you see instead?
I expected it to understand the outer black dots and use them instead. 

Please provide any additional information below.

Original issue reported on code.google.com by tasoman...@gmail.com on 6 Aug 2013 at 10:39

[GoogleCodeExporter]

Original comment by romannu...@google.com on 6 Aug 2013 at 2:06

• Added labels: Component-AssetStudio, Type-Enhancement
• Removed labels: Type-Defect

[GoogleCodeExporter]

Original comment by romannu...@google.com on 13 Aug 2013 at 5:05

• Changed state: Fixed