Refactor RFFormContentProvider
Refactor RFContainer to support `- visibleFields` semantics
Add `- filterNot:` and `- filterNotEmpty` to collection operations
Test RFMockFormElement
Add a method for creation of a mock element with array
Rename spec of the ordered set diff composer
Rename RFSignalContainer to RFSwitch

Rename RFSignalContainer to RFSwitch hence this name is more intention
revealing
Refactor RFSwitch
Fix the method for creation of RFVAlidator with NSRegularExpression
Refactor RFSeciton
Refactor RFField to the visibleFields semantics
Run pod install on example project