Prepatory tidy-up
Start of work for Server config to be in config.groovy

HostVerifier uses values from config as well as the database (for now) to verify proxy requests
dos2unix on HostVerifier
getInfo call in ServerController

supports getting server information from config file
LayerStore: use server info to get layer type
tidy up layer store

remove redundant calls to spyOn publish
remove callback code in layerstore
Merge pull request #1448 from aodn/servers_from_config

Servers from config
Use HTTPS version of depth service by default
Merge pull request #1462 from aodn/depth_service_https

Use HTTPS version of depth service by default
Rename metadata to extraLayerInfo to avoid confusion
Merge pull request #1463 from aodn/rename_ncwms_metadata

Rename metadata to extraLayerInfo to avoid confusion
NcWMS: async date loading

on slower machines dates loading can jam the browser as it was done
inline. the solution is to interleave it and load every year in an async
manner. this lets the browser regain control and the experience is more
responsive
NcWMS: interleave with setTimeout when date loaded

if a date is already loaded, use setTimeout to ensure the first thing we
do is release control back to the ui, resulting in a happier user