[cap2hccapx.c] support ppi packet header from kismet

[ChrisLundquist]

Add support for PPI packet headers as created by Kismet.

$  ./cap2hccapx.bin ~/wifi/Kismet-20170512-19-06-01-1.pcapdump test.hashcat
/home/clundquist/wifi/Kismet-20170512-19-06-01-1.pcapdump: Could not read pcap packet data
Networks detected: 305
[*] BSSID=<redacted>  ESSID=<redacted> (Length: 14)
[*] ....
...
Written 50 WPA Handshakes to: test.hashcat

$ hashcat -a 0 -m  2500 ./test.hashcat ./rockyou.txt 
hashcat () starting...

OpenCL Platform #1: Apple
=========================
* Device #1: Intel(R) Core(TM) i7-3740QM CPU @ 2.70GHz, skipped.
* Device #2: HD Graphics 4000, 384/1536 MB allocatable, 16MCU
* Device #3: GeForce GT 650M, 256/1024 MB allocatable, 2MCU

Hashes: 50 digests; 37 unique digests, 12 unique salts
Bitmaps: 16 bits, 65536 entries, 0x0000ffff mask, 262144 bytes, 5/13 rotates
Rules: 1

Applicable optimizers:
* Zero-Byte
* Slow-Hash-SIMD

Watchdog: Temperature abort trigger disabled.
Watchdog: Temperature retain trigger disabled.

Dictionary cache built:
* Filename..: ./rockyou.txt
* Passwords.: 14344391
* Bytes.....: 139921497
* Keyspace..: 14343296

[s]tatus [p]ause [r]esume [b]ypass [c]heckpoint [q]uit => s

Session..........: hashcat
Status...........: Running
Hash.Type........: WPA/WPA2
Hash.Target......: ./test.hashcat
Time.Started.....: Sun May 14 10:49:21 2017 (2 secs)
Time.Estimated...: Sun May 14 16:15:08 2017 (5 hours, 25 mins)
Guess.Base.......: File (./rockyou.txt)
Guess.Queue......: 1/1 (100.00%)
Speed.Dev.#2.....:     3475 H/s (8.14ms)
Speed.Dev.#3.....:     5226 H/s (5.56ms)
Speed.Dev.#*.....:     8912 H/s
Recovered........: 0/37 (0.00%) Digests, 0/12 (0.00%) Salts
Progress.........: 639812/172119552 (0.37%)
Rejected.........: 631620/639812 (98.72%)
Restore.Point....: 0/14343296 (0.00%)
Candidates.#2....: thekillers -> overtime
Candidates.#3....: 123456789 -> hotandsexy

[jsteube]

This is great, thanks!