add authentication infrastructure:  secrets for devices, hashing and access tokens.   add test fixture infrastructure to enable us to test this, and lots of cleanup and fixes.
Merge branch 'master' of https://github.com/magentajs/service
default to platform's choice of node
surround headwaiter json results with endpoints
Merge branch 'master' of https://github.com/magentajs/service
turn on authentication for messages.index.   add support with fixture for device accessToken and tests
use populate on principal, move middleware out to modules
precompute auth header so we can use it throughout tests
add auth to message get and add tests to make sure message principal exists
add authentication to message post endpoint
add tests to confirm no unauth'ed access to message endpoints
clean up deps and requires
send secret down as part of device principal create, but only device principal create.
turn on auth for blobs and principals as well minus POSTing blobs.  turn on real security config.
minor logging revisions
dynamically set config http port if not already set in config
move http_port to configuration to config file.
use endpoint urls internally
check for missing email or password before creating user principal
don't allow principal to be created if its primary key exists