initial implementation of request forwarding, cookies set from dbwriter are still not being properly passed through - issue #460

improve per-process informational debug output about what WSAPIs are supported, their requirements, and how they are handled (forwarded or handled locally?) - issue #460

This reverts commit 019857e3.

add the dbwriter process.   it's not yet hooked up, but starts up and runs, and included in health check.

reorganize browserid process - break out view serving and wsapi handling.  preparation for dbwriter split.  issue #460