Should we remove the included GWT SDKs from the plugin?

Why we maybe should remove the SDKs.
- I think nobody is using all of the included SDKs at once
- GWT 2.10 is missing
- Only the main Versions are included. GWT 2.8.2 for example is missing.
- Increases the download time of the plugin
- Increases the build time
- Increases the disk consumption
- It's easy to specify your currently used version

Maybe somebody could create an Popup that asks for a GWT version if no SDK is configured.

Any thoughts on this?

首先查看插件目前如何包含 GWT SDKs，以及用户如何配置 SDK。明确目标是移除捆绑的 SDK、为未配置的版本添加提示，还是两者都要；在范围和实施计划达成一致后，才算完成。

由索引模型根据 Issue 内容生成。