Integration Test

Minor code refactoring:

* Move the daemon running and command running code out of src/Vault.hs into src/DaemonRunners.hs and src/CommandRunners.hs, enabling reuse in test cases
* Various build fixes cleanup that was lingering

Logging improvements:
* Improved signal handling in vault binary. 
* Ability to toggle between debugging and normal at runtime

Integration testing:
* Preliminary integration test suite in tests/IntegrationTest.hs. Nothing exhaustive at present; writes a single point and retrieves it from vault, but implements all the scaffolding for a larger test of the complete cluster.

AfC