The signature for the TRX header is still incomplete for v1. According to http://wiki.openwrt.org/doc/techref/header, offset[0] = lzma-loader, offset[1] = Linux-Kernel and offset[2] = rootfs.

Before the fix:

bernardomr@splinter ~/openwrt $ binwalk openwrt-wrtsl54gs-squashfs.bin 

DECIMAL       HEXADECIMAL     DESCRIPTION
32            0x20            TRX firmware header, little endian, header size: 32 bytes, image size: 1323008 bytes, CRC32: 0x6CAC483, flags: 0x0, version: 1, kernel offset: 0x1C, rootfs offset: 0x8D8
60            0x3C            gzip compressed data, maximum compression, from Unix, NULL date:
2296          0x8F8           LZMA compressed data, properties: 0x6D, dictionary size: 8388608 bytes, uncompressed size: -1 bytes
517152        0x7E420         Squashfs filesystem, little endian, version 2.1, size: 805671 bytes, 269 inodes, blocksize: 65536 bytes, created: 2014-10-29 18:53:25

After the fix:

bernardomr@splinter ~/openwrt $ binwalk openwrt-wrtsl54gs-squashfs.bin 

DECIMAL       HEXADECIMAL     DESCRIPTION
--------------------------------------------------------------------------------
32            0x20            TRX firmware header, little endian, header size: 32 bytes, image size: 1323008 bytes, CRC32: 0x6CAC483, flags: 0x0, version: 1, loader offset: 0x1C, linux kernel offset: 0x8D8, rootfs offset: 0x7E400,
60            0x3C            gzip compressed data, maximum compression, from Unix, NULL date:
2296          0x8F8           LZMA compressed data, properties: 0x6D, dictionary size: 8388608 bytes, uncompressed size: -1 bytes
517152        0x7E420         Squashfs filesystem, little endian, version 2.1, size: 805671 bytes, 269 inodes, blocksize: 65536 bytes, created: 2014-10-29 18:53:25

- Loader: 0x20 + 0x1C = 0x3C
- Kernel: 0x20 + 0x8D8 = 0x8F8
- RootFS: 0x20 + 0x7E400 = 0x7E420

This patch fixes some cases in running binwalk:

 - from build dir: src/scripts/binwalk
 - from repo dir: src/build/binwalk
 - from custom dir, but without full path: ./binwalk
   (`dirname(dirname('./binwalk'))` becomes an empty string which is
   treated as "current working directory" while the expected output is
   "..")

While `unzip` has problems with extracting certain zip files[1], `7z`
does properly handle this test file. There is no reason to stick to
`jar` now.

Fixes #101.

 [1]: http://www.openipcam.com/files/Firmware/Foscam/FI8908W-fw11.14.1.46.zip

Added extractor.directory attribute which contains the absolute base extraction directory; fixed extraction path name cration bug.

This commit allows to combine --red, --blue and --green options instead of the mutual exclusive behavior.
It is therefore possible to show, for example, only red and blue, that it to say every pieces of files that have changed.