Servers from config

@danfruehauf took over.

This PR now includes:
 * Servers in config file (work by @dnahodil)
 * Controller function `server/getInfo` - returns server information from config file
   * Tests
 * JS code to use `server/getInfo` and act on the server type
   * Remove the ugly hack of looking for ncwms layers by having `/ncwms/wms` in the URL

This can now be reviewd.

# Original message by @dnahodil:

*Ready for someone to take over - feel free to contact me for any questions*

This is a start on the work to have Servers configured in config files rather than in the database. I have added Server config to config.groovy in a way that I think will work but feedback on this approach is welcomed. I have updated HostVerifier so that proxy requests use the new Server configuration to validate proxy URLs. There are other usages of Servers which haven't been changed over, yet.
No argument about that.

That whole class will look different after we get rid of `findLayerAsJSON`. I think leave it like that for now and in the next round of statelessness clean this. The polymorphism should come from the underlying class it instantiates.