Add possibility to define filter chains via static method

[dominikschlosser]

Something like:

@ProcessorProvider(methodName = "providingMethod")
private String csvField;

public static CellProcessor providingMethod(){
    return new Optional(new MySuperComplicatedProcessor(42, "bla"));
}

Adds additional flexibility and support for processors which can not be configured purely by annotations (same processor more than once, parameter types not supported in annotations, ...)