Read/Write EFcfis/EFcphs-cff files

Hi, This patch reads and writes the call forwarding unconditional status from and to the SIM depending on the SIM file availability. New property needs to be added due to the fact that number won't be available from the cphs-cff file. Incase of SIM, EFcphs-cff file holds call forwarding status and it is represented as a flag. In case of USIM(EFcfis), we have the status flag and also number.So, adding new property for status and using the existing VoiceUnconditional with number will work for both SIM and USIM cases. Other option is to have 2 properties, "VoiceUnconditional" and "Number". "VoiceUnconditional" will have the status of the call forwarding( "enabled", "disabled") whereas the "Number" property will have the call forwared number. offline-online state transitions results in caching the call forwaring status every time. To avoid this, call forwarding atom is moved to the post sim and its moved also due to the fact that call forwarding status doesn't change in roaming. Regards, Jeevaka