StubRunner should first look for stubs in a local repository

StubRunner will first look for stubs in local repository and only if it's not found will pull from remote.
This behavior can be overridden by the new property `stubrunner.skip-local-repo` (default: `false`) - changed the previous `use.local.repo`.
Imho, this should be the default behaviour (just like Gradle/Maven dependency resolvers work)