Add support for @ModelAttribute

[Gearme]

Controller method parameters annotated with MVC's @ModelAttribute currently do not get represented in HAL. Adding support for that Annotation (provided explictly or implicitly) would be appreciated. @gregturn suggested that QueryParameter, currently responsible for @RequestParam, could be modified to cover that Attribute as well.

Note that RFC6570 - aside from its form-style query expansion - also defines a composite value using an "explode" modifier ("*"). Support for @ModelAttribute could conveivably take either shape, or even offer that choice to the developer in some way.

style	example
simple form style	{?field1,field2,field3,page,size,sort}
with composite value	{?myClass*,page,size,sort}