Create common device-host comms module

[solidpixel]

This issue covers the creation of a piece of common library functionality to implement communications between the device and the host.

Basic goals:

• Communications will use a multi-user sub-pub model:
  • Using sub-pub with handlers allows multiple components to share a common network link.
  • The host is the server side of the connection, layer is the client.
  • All comms are initiated by the client.
• Client library will be C++, and host library will be Python.
• Communications protocol will support:
  • Sync reads
  • Sync writes
  • Async writes
  • Sync read-write
• Client logging producer/consumer provided.
  • Goal is to swap out logcat for something reliable.
• Virtual file system producer/consumer provided.
  • Goal is to allow read/write from host file system for easy to edit asset swaps.
• Load-time config from file provided.
  • Goal to allow load-time parameterization of a layer from a file on the host.
• Simple interactive config terminal provided.
  • Goal is to allow simple interactive configuration at load time.
  • Goal is to allow simple "Press a key to make the layer do something" triggers.

On Android:

• Use TCP/IP socket on the host.
• Use Unix domain socket on the device.
• Use adb reverse localabstract:<device uds> tcp:<host port>

[solidpixel]

Implemented by #11