FYI, I've begun the process of restoring the FAT and HFS file system resizing capability to the parted package. Those capabilities will reappear, but not in libparted proper. They will be provided by a separate library that will be useful only in conjunction with libparted.
I expect to use most of what was in libparted/fs/hfs/ and libparted/fs/fat/, along with a few functions from libparted/filesys.c.