Create RelationshipRepository for custom queries

And move getting relationships methods to it.
Extracts the permissions setting

Also add permissions setting after cache clearing
Add Thread entity
Schools: Create structure
Schools: Add parser for vk database
Schools: Add fixtures
Schools: Add CategoryController
Schools: Add CategoryType
Schools: Add template for category_widget
VDolgahAdmin: solve problem with writers for collection types

problem: field not added if property writable via
"add" and "remove" methods.
example: $cities, addCity($c), removeCity($c), getCities()
Schools: Add posibility to hide field in child form
Schools: Add SchoolAdmin
Add Paginator as Service
Schools: Add CategoryService
Schools: use CategoryService in CategoryController
Use ReflectionClass->getShortName instead basename
Fix country field in school list
Schools: hide cities, universities, schools field

due to big amount of data
Add new line and the end of file