reimplement android mkbootfs with pure java, features include:
unpack:
- using commons.compress
- save cpio entry info on unpacking, and reload it on packing, this is
called 'exact-matching'
pack: using new code with the help of commons.compress
- for newly added ramdisk file, its file mode falls back to
'pattern-matching'
- for newly added ramdisk file that doesn't match any pattern, it will
use default file mode, 'default'
integration test:
- enable strict cpio checking