Start refactoring of service object

Planning towards integration of git repositories checkout.
Merge branch 'master' into refactoring_service
Url defaults to localhost
Add logic to find main module from metadata
Add example of adapter layout
Fix to_json in service object
Remove dead code
Create dockerfile and build from code_dir
Change dockerfile template for new service struct
Change examples to be more visible
Rearrange options for registering
Make identifier function more explicit
Convert method to static
Stub code and git repo registration functions
Add name of the adapter to service object
Forgot to import the function adapter_iden
Move some registration code to services module
Refactor registration of posted code
Extension list should be in service module
Import extensions in services