Add a missing license header.
Remove semaphores and add +CRTDCP to support async operation.
Fix delete context and disconnect to execute just once.
Add support for NONIP PPD type.
Change CellularNetwork::clear() to virtual so it can be overridden.
Removed CellularBase and AT_CellularBase from cellular stack and updated both code and unittests accordingly.
Moved property handling into AT_CellularDevice