Cross-Library messaging and permissions

Circuitboard is a libraray designed to standardise and approach to cross-library messaging at an application-level

It is a collection of interfaces to allow for:

• Aggregation of messages from multiple sources
• Gated Messaging which is the ability to control whether messsages which interact with state will affect the system. ( i.e. Message-Mocking)
• A custom exception type bearing custom error codes