This completes the migration of swagger processing from strong-remoting
into loopback-explorer.
Added additional usage instructions to README and additional testing.
This commit introduces a change into where resource descriptors
are hosted. They are no longer hosted under /swagger, but instead
under the same path as the Explorer, wherever that may be.
Generally, the resource listing will be available at
/explorer/resources, and api listings under
/explorer/resources/{modelName}.
LoopBack REST adapter owns the whole URL space and does not let other
middleware handle same URLs. It's possible to circumvent this measure
by installing the explorer middleware before the REST middleware.