(PE-2320) Clean up core namespace

Refactorings include:
* Extracted config code into own namespace
* Pushed bootstrapping functions down into bootstrap namespace
  - Left forwarding function in core for accessible API
  - Renamed bootstrap* to bootstrap-services
* Moved compile/instantiate functions into app namespace
* Converted let blocks into -> pipelines
* Consolidated and cleaned up bootstrap testutils
Merge pull request #97 from nwolfe/pe2320-cleanup-core

(PE-2320) Clean up core namespace