In lang-addon.xml, when a custom component extends another component e.g. decimalbox, especially for inheriting ZK original data binding setting in zkbind.jar/lang-addon.xml, <depends> is usually required.

If missing, it will produce data binding failure because of different class loading order in different platform, e.g. zkbind.jar is loaded after the custom component, then built-in data binding setting inherited from ZK component (decimalbox) is not applied to the custom component.
And it's hard to identify this failure caused by class loading because the problem will not always happen.

If we can improve the checking for this case, it will avoid such problem in the future.

For example, show a warning like a component in <lang-addon> that extends another component but no <depends> specified