registerRpc & createRpc

small changes

reject an rpc as 0 is converted to null

reject an rpc as 0 is converted to null

reject an rpc as 0 is converted to null

Implemented dop.getRequest

updated package.json

Mutations properties are underscore styled

Changed protocol (undefined is now delete instruction)

Merge branch 'features'

* features:
  Bug fixed when unsubscribe and resubscribe same object
  Allowing registrable Classes