Adding ActivityEngine::EntryBuilder

In moving towards the builder I'm envisioning command plugin options.
Also capturing any configurations for thos registries and evaluating
them when the behavior is invoked.
Updating require order for engine

I'm looking towards the Spree initializer structure as Ryan Bigg is
likely the definitive expert on Rails engines.
Adding ActivityEngine::EntryBuilder

In moving towards the builder I'm envisioning command plugin options.
Also capturing any configurations for thos registries and evaluating
them when the behavior is invoked.
Extracting entry builder commands
Adding ActivityEngine.for_models builder method

Refactoring interface for builder
Removing require activity_sweeper

This will fail if the Rails framework isn't loaded.
Adding specs for abstract command object
Tightening up tests

Since we are delegating commands, I don't want to test the stubs but
isntead would rather test that the builder responds to the command
Removing unused high level method

It is now a lower level responsibility
Tidying up RegisterCall

Providing means of overwriting collaborating classes
Demoting register_models and register_controllers

I want these methods invoked in a lower level block.
Removing some of README as it lied!
Renaming register -> register_controller generator
Merge branch 'version-0.1'

* version-0.1:
  Renaming register -> register_controller generator
  Removing some of README as it lied!
  Demoting register_models and register_controllers
  Tidying up RegisterCall
  Removing unused high level method
  Tightening up tests
  Adding specs for abstract command object
  Removing require activity_sweeper
  Adding ActivityEngine.for_models builder method
  Extracting entry builder commands
  Adding ActivityEngine::EntryBuilder
  Updating require order for engine
  Adding ActivityEngine::EntryBuilder

Conflicts:
	lib/activity_engine.rb
	lib/activity_engine/engine.rb
Bumping to version 0.1.0