New script: samsung-split-broken-tar-md5.py

I was not able to let Odin flash official ROM for
Samsung GT-S5360 found on
  http://samsung-updates.com/device/?id=GT-S5360
like S5360XXLK3_S5360XEFLL1_S5360XXLK3_HOME.tar.md5

Those tar.md5 files should be a tar file followed by
its MD5 sum, more precisely it can be generated by
the following commands:
  $ tar cf XXX.tar file1 file2 ...
  $ cp XXX.tar XXX.tar.md5
  $ md5sum XXX.tar >> XXX.tar.md5

But those tar.md5 files are corrupted:
  $ tar tvf XXX.tar.md5
  tar: This does not look like a tar archive
  tar: Skipping to next header
  tar: Exiting with failure status due to previous errors

Here is the beginning of an hexa dump:
  $ hd XXX.tar.md5
  00000000  73 62 6c 2e 62 69 6e 00  00 00 00 00 00 00 00 00  |sbl.bin.........|
  00000010  00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00  |................|
  *
  00000070  00 00 00 00 00 00 00 00  00 00 00 00 30 30 30 30  |............0000|
  00000080  34 37 37 30 30 30 30 00  00 00 00 00 00 00 00 00  |4770000.........|
  00000090  00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00  |................|
  *
  00000200  13 00 00 ea fe ff ff ea  fe ff ff ea fe ff ff ea  |................|
  00000210  fe ff ff ea fe ff ff ea  f8 f0 9f e5 fe ff ff ea  |................|
  00000220  04 e0 4e e2 ff 5f 2d e9  0a 03 a0 e3 0d 00 50 e1  |..N.._-.......P.|
  00000230  07 00 00 ca 76 6a 00 eb  0a 03 a0 e3 0d 00 50 e1  |....vj........P.|

There is a 512-byte header record, followed by file contents.  A
normal header record contains many informations, but here there are
only the file name (sbl.bin in the example above) and its length
(4770000 in octal, i.e. 1306624 bytes).

This script uses these informations to extract files, and generated
the 3 tar.md5 files needed by Odin.
New script:  unpack-boot-img.py

Unpacks a boot.img file and prints the mkbootimg command line
to repack it.