Namespace should be more flat

[Stiivi]

Problem: Rethink the module structure - it might be confusing. Currently some module namespace is there just for taxonomy reasons.

Make requirement to import just brewery: user will get everything except backend-related stuff.

That does not mean that the modules will be removed, just users will NOT be encouraged to use them. Rules:

• no example should show use of sub-modules, except when backends are involved
• documentation should contain reference for 'un-moduled' objects
• in documentation there should be a note, if there is any reason that user would want only one Brewery module, he might.

Considered as usability change.

Users should not have to ask "What package this class/function is in?"