S4-120 ensure application-singleton scopes for more dependencies

- use @Singleton annotations where applicable, in(Scopes.SINGLETON) otherwise (providers)
S4-116 remove duplicate binding for RemoteEmitters
S4-120 Prefer @Singleton for app singleton
Merge branch 'S4-120' into dev

Conflicts:
	subprojects/s4-core/src/main/java/org/apache/s4/core/DefaultCoreModule.java
	subprojects/s4-core/src/main/java/org/apache/s4/core/S4Bootstrap.java