Rudder

We want to be able to track modification done to configuration entities (Directive, NodeGroup, Rule), and so we want to split write action from read ones.

Moreover, we want to merge related entities into one repository, so that shared set of items are managed by only one repository at a time (and so, we will be able to simplify interaction with underlying, hierarchical storage).

In practice, that means:

• Merge ActiveTechniqueCategoryRepository, ActiveTechniqueRepository into DirectiveRepository
• and then split DirectiveRepository into RoDirectiveRepository and RwDirectiveRepository
• Merge NodeGroupCategoryRepository into NodeGroupRepository
• and then split NodeGroupRepository into RoNodeGroupRepository and RwNodeGroupRepository
• split RuleRepository into RoRuleRepository and RwRuleRepository