Support loading multiple image resources at once

[aspsnd]

Expected Behavior

It is expected that one resource description can load multiple similar resources

Current Behavior

Now a resource description can only specify one image

Possible Solution

Steps to Reproduce

Environment

• Eva.js version: e.g. 1.0.0
• Browser & Version: e.g. Chrome 67
• OS & Version: e.g. MacOS 10.15.7
• Running Example: url

[fanmingfei]

支持多个图片的 spine dragonbone