Add FIFO job server protocol

[jkloetzke]

Is your feature request related to a problem? Please describe.
Bob does not support the FIFO based job server protocol of make. See the make manual for details. This prevents us from merging BobBuildTool/basement#282 until Bob catches up.

Describe the solution you'd like
Add FIFO job server protocol support, both as a server and a client.

We should retain backwards compatibility and enable the FIFO protocol only based on a policy.