Exceptions modification.

* All exceptions extend java.lang.RuntimeException to avoid necessity of checking exceptions manually
* There are two new exceptions in the com.gadgetkeeper.yoote.transport package
Significant Caster modification.

* Caster has two type parameters V and T
* Caster casts value of type V into value of type T
* Caster doesn't require Class<V> in cast method
* There are few renames and javadoc modifications in engine classes
Switch to bounded wildcard in engines' constructors.

* check argument of services