Add more config properties

[flyingsky]

1. defaultTheme to set default theme, before value is always 'default'.
2. syncSettings to disable auto sync settings.json if set it to false.
3. Add events property in config when embed admin in app, so it doesn't limit use events.js, we can use typescript.

[flyingsky]

The latest pwd module doesn't release, so we need wait, but the source code is changed.