Writing to Java beans

[krzemin]

As we now support reading from Java beans, for completeness we could also implement support for writing to them.

Let's assume that Java bean is a class that:

• have public, no-arg constructor
• for each target private field foo of type T it has a method of following signature def setFoo(value: T): Unit

IMO it's OK to provide initial support that covers only a case, when we have all the required data in the source object. In the scope of this ticket it's not necessary to make dsl operations like withFieldConst, withFieldComputed, withFieldRenamed working with Java beans targets.

[krzemin]

Basic support implemented in #93