Scanning jars for classpath resources

[czyzby]

During compilation, jars should be inspected and any classpath resources should be copied along with the rest of the assets. Default LibGDX include some extra assets (shaders, font) that we would otherwise have to copy "by hand" - and even if we included those assets manually, Dragome would still lack support for useful third-party extensions with custom assets like VisUI (which includes some default GUI skins).

@fpetrola I'd like your input (or help) on this. Is there a way to hook up to the Dragome compiler, inspect the jars and copy non-.class resources to assets?