Refactoring: Separate "Engine" and "Topology" layers

[nathanwbrei]

JANA2's internal architecture can now be divided into four distinct layers: {Plugins, Components, Topology, Engine}

In practice, this mainly consists of moving files around for now. Several abstractions have also changed slightly:

• JProcessingController and JArrowProcessingController have merged, as this level of indirection is obsolete and holding up some overdue improvements to JArrowProcessingController. Similarly, JPerfSummary and JArrowPerfSummary, which always had an awkward relationship with each other, have merged.
• The anemic JArrowTopology class has rejoined JTopologyBuilder, cleaning up the service dependency chain as follows:

JPluginLoader <-> JComponentManager <- JTopologyBuilder <- JProcessingController