Do not fail on circular constructor/setter dependency

_From [stepan.koltsov](https://code.google.com/u/113939464116033188989/) on March 07, 2012 14:42:18_
#

public static class A {
    private final B b;

    `@`Inject
    public A(B b) {
        this.b = b;
    }
}

public static class B {
    private A a;

    `@`Inject
    public void setA(A a) {
        this.a = a;
    }
}

public static void main(String[] args) {
    Guice.createInjector(new AbstractModule() {
        `@`Override
        protected void configure() { }
    }).getInstance(A.class);
# }

guice reports error:
#
# Tried proxying com.company.Temp$A to support a circular dependency, but it is not an interface

Proxy is not needed here: guice should just create "B" first, inject it into "A" constructor and then inject "A" into "B".

_Original issue: http://code.google.com/p/google-guice/issues/detail?id=690_