fixing ServiceController NPE
revisited class & constructor access modifiers - exposing as less as possible
refactoring service setting from ServiceContext to ServiceBuilder to allow dependencies passing to service constructor
eliminated NEVER & PASSIVE service modes
Removing useless DependencyFlag methods.

MSC2 API users don't have access to MSC2 controllers.
Thus there's no getter for DependencyFlag(s) and so
providing DependencyFlag.in() methods doesn't make a sense.

WRT MSC2 implementation we will translate dependency flags
to bits array so these methods are good-for-nothing also from impl. PoV.
eliminated ANTI, UNREQUIRED & REPLACEABLE dependency flags
removing ServiceBuilderImpl synchronizations - the implementations of ServiceBuilder are not thread safe