Proxy configuration for individual web services

For a user wishing to use Jalview + a local intranet JABAWS + external services accessed via proxy, it is currently only possible to have Jalview contact services either directly, or via a proxy. Ideally, however, intranet resources should be accessed directly, but external resources (e.g. databases and DAS servers) must be routed via the external proxy.

Suggestion is to have checkboxes for JABAWS server configurations (and other service URLs) to indicate if they should be accessed directly or via the configured proxy.