add theme uri with a themeProvider extend StandardThemeProvider form zul
will break StandardThemeProvider form zkmax(or any others) behavior
provide a better way to maintain the theme uri list.
let developer can dynamically add theme uri without breaking each ThemeProvider.
a composible(not extend) ThemeProvider
or add more method like addThemeURIs(...) and make sure it works
I am trying to provide themes in an zk add-on(calendar) with registry its own themeProvider witch extends StandardThemeProvider form zul.
However there are others in zkex and zkmax and then even some customers extend those.
in the end there can only be one configured in the system.