RES-192: get rid of the global cache

- find functions are not public anymore we create the find module for future use
- everything is done using callbacks
- no cache mean the createProcess always create a new process never retrieve one. This will be done by managers.

- core tests are adapted
- the rest server will need managers so it does not work at this point
RES-192: add process manager
RES-192: adapt rest server
RES-192: update public interface
RES-193: interface for BPMN as XML string and Javascript String
RES-192, RES-193: update readme
RES-193: replace Standalone by UnManaged
0.2.0