Fix #175: Cannot call #fields.detailedErrors() from a Spring Webflow form

[TheConstructor]

Using #fields.detailedErrors() with spring-webflow 2.3.1 will call its org.springframework.webflow.mvc.view.BindingModel.getFieldErrors(java.lang.String) with "" as argument. However specifing "" leads to the error that a non-empty prefix is expected; calling the parameter-less version works as expected.

I checked back into the repository and the behaviour is unchanged since 2.3.1:

• getFieldErrors(java.lang.String) delegates calls new FieldPrefixErrorMessage(String) when the input ends in *, removing the last character
• new FieldPrefixErrorMessage(String) then asserts that a non-empty prefix is given, which will result in an exception as the only character was removed.

Feel free to propose another fix, but from what I see in spring-webflow's BindingModel there are not many other approaches. Probably calling getAllErrors() would also be an option, too.