Method returning array of custom flags
Method storeFlags supports custom flags
Merge branch 'feature/custom-flags' into develop
Method to store cusotm flags is separate from the original one
Fixes in storing custom flags; possible to append new messages with custom flags
Default NULL value for custom flags in append and storeFlags function arguments for backwards compatibility
Merge pull request #572 from michalkalis/master

Added method to store custom flags and a property to access custom flags