Refactor format of teh compiled Javascript templates.

New format is close to RequireJS module. The following differences are exist:
  - Namespace variable is created as before.
  - Function to create module is excuted immediately.

These changes should allow following improvements:
  - Completely hide all helpers from clients.
  - Include only required helpers.
  - Simplify integration of the user-customizable parts like
    custom print directives.

I'm planning to create more intellectual generator to implement such improvements and handle custom print directives in RequireJS backend.