Improve legacy bean support via overrides arg to getBean()

[seancorfield]

When migrating existing code to FW/1 & DI/1, it would be convenient to be able to tell getBean() "Hey, here are the constructor arguments I want you to use (instead of looking in the factory)!":

var foo = factory.getBean( "foo", { arg1 : 1, arg2 : "two" } );

These could simply be dynamic overrides for the bean being created (augmenting the optional overrides that a bean can be declared with).

This is a very common request and even tho' I nearly always push back and say "That's the wrong way to do it -- use an explicit factory (bean) instead", it actually doesn't look all that difficult to implement (unless I'm missing something obvious that has prevented me from wanted to undertake this in the past!).

[seancorfield]

Dan confirmed this is acceptable (although he had a problem with dotted paths... because that's a fussy s.o.b. and I wish I could figure out a completely universal solution!). Will write tests and documentation when I'm back at base.

[seancorfield]

Added constructor argument support to parent getBean() call. This is "safe" insofar as ColdSpring and WireBox will ignore it, but it would be better to trap a non-DI/1 parent and throw an exception (rather than just hiding the fact such parent bean factories might silently ignore the extra arguments -- or worse a custom factory bean may do something wrong if it accepts an extra argument there and we pass it something unexpected).

[seancorfield]

Tests added. Documentation clarified.