This commit adds the ability to collect licensing information from the dependencies of software definitions that are not defined in omnibus. We use license_scout gem in order to collect licensing information from the dependency managers used by the software. Since many softwares are not using dependency managers we are also including some options to enable/disable collection of licensing information:

1. New software dsl method 'skip_transitive_dependency_licensing'
When set omnibus will skip collecting licensing information for the dependencies. By default this is set to false.

2. Temporary configuration value 'fatal_transitive_dependency_licensing_warnings'
When set omnibus will fail the build when there is a warning from transitive dependency license collection. We are introducing this as a feature flag while we are implementing support for new types of dependency managers in license scout. Once we implement license detection for most commonly used set of projects, we will remove this configuration opt...