Implement actual loading of a sb1 file to a structure in full
generality. Also implement dumping for debug purpose
Change-Id: I320035ea628719480a79aaccb05dce9a83256927
In the case of encrypted SB files without any key match, it is
still possible to dump the section headers. The force option
allows one to do so. It also allows to dump unencrypted sections
of encrypted files if there are some.
Change-Id: I36280230679ac5903f9c451c68c276f5c6959536