Don't rely on information in serviceCache.json

Fixes "gatherLinks" message to only return available services.

Jira-issue: WP-1002
Merge pull request #12 from aldafu/WP-1002-build-serviceCache-from-available-mods

Don't rely on information in serviceCache.json
Fix service discovery not being found

As part of the others fixes for WP-848 this was missing. webinos.discovery
is now defined in the discovery wrt code itself.

Jira-issue: WP-848
Merge pull request #13 from aldafu/WP-848-fix-missing-discovery

Fix service discovery not being found