Added new custom errors for args
Added a helper for logging method calls
Added controller-level exception handling
Updated custom errors (fixing naming conflicts)
Added MethodLoggerHelper to Backend (debugging)
Updated arg handling in BackendApi (WIP)

* Not working right now, rOCCI-core is broken and doesn't
  type Resource instances properly
Updated the hook subsystem, basic integration
Passing options from config to hook instances
Added custom hook errors
Added deps checking on hooks

Hooks can now specify a required backend.