Clean up webinos namespace declaration.

webinos namespace is explicetely declared on the global window object
(here named exports). Also add a private namespace _webinos which is only
available inside webinos.js for private functionality, like registering
service constructors.

Jira-issue: WP-1045
Update Test API Get42 to register its contructor

The name for API module constructors is no longer hard coded, so APIs
have to register

Jira-issue: WP-1045
fix undefined errs for _webinos

increase backwards compatibility

Jira-issue: WP-1045
Merge pull request #28 from aldafu/WP-1045-register-service-constructors

Wp 1045 register service constructors