Abstract package metadata for multiple platforms

[ricobl]

Metadata files like webOS' appinfo.json should be generated from config on the package.json file.

Additionally, the config should allow extending specific platform metadata.

Here is a proposal of the data structure to accomplish this:

{
  "react-tv": {
    "metadata": {
      "generic": {
        "id": "react.tv.app",
        "title": "playkit-tv",
        "...": "..."
      },
      "webos": {
        "vendor": "webos vendor"
      }
    }
  }
}

• generic is should be common to multiple platforms
• webos and others should contain platform specific info