Add CopyTargetByteArray. CopySourceByteArray is not implemented yet.
This is only suitable for reading small amount of data such as GPT header
or FAT boot sector location. Not meant for copying whole partition because
data has to be transfered over DBus.
Differential Revision: https://phabricator.kde.org/D16487
setFlags function now takes additional argument const Partition& partition.
This allows us to completely remove CoreBackendPartition class.
Remove getPartitionBySector and getExtendedPartitions.
These functions were designed around libparted API and are not very convenient
with other backends.