paging-results - regenerate only v2 api

paging-results - hardcode /katello until apipie works
paging-results - more system-groups updates
Merge pull request #11 from thomasmckay/paging-results

Paging results
Reflect the changes in generating the bindings from Katello as an engine.
Merge pull request #12 from iNecas/katello-engine

Reflect the changes in generating the bindings from Katello as an engine.
Update api from products controllers