Add pipe argument

[jacobrosenthal]

Wireshark supports pipes natively now as of 2.3
https://devzone.nordicsemi.com/question/79845/nrf-sniffer-support-for-wireshark-v203/

For the "simple user" with NRFsniffer1.0.1 here is a basic help on how to use wireshark 2.3.0 or more (note it will be simplified if Nordic does an update of it's nRFsniffer):

open the sniffer
open wireshark
go to capture->options->manage interfaces...->pipes
add \.\pipe\wireshark_nordic_ble in the field
press OK and start the capture on this interface (for me I have to press several times for it to work)
For the first time only you open Wireshark:

go to edit->preferences->protocols->DLT_USER
edit the encapsulation table and add "user10 (DLT=157)" with "nordic_ble" in payload protocol field.

@cdealti implemented pipes in his fork https://github.com/cdealti/Adafruit_BLESniffer_Python/ but overwrote the logging so I figured you wouldn't take it as a PR. I kept his cleaner reporting (which I can remove if its a dealbreaker) and brought in his pipe work as an argument. I could see disabling file logging if you enable pipe, but I left it for now.

Looks like this now with verbosity off

Jacobs-MacBook-Air:Adafruit_BLESniffer_Python jacobrosenthal$ python sniffer.py /dev/tty.usbmodem1411 -p
Capturing data to logs/capture.pcap
Connecting to sniffer on /dev/tty.usbmodem1411
Scanning for BLE devices (5s) ...
Found 8 BLE devices:

  [1] "" (00:22:D0:2A:E4:A3, RSSI = -64)
  [2] "" (33:B2:5F:DA:48:D6, RSSI = -103)
  [3] "" (B0:03:4B:F1:75:F3, RSSI = -50)
  [4] "" (D0:03:4B:45:EC:F1, RSSI = -103)
  [5] "" (D0:03:4B:31:75:F2, RSSI = -103)
  [6] "" (0B:F2:C4:87:78:2C, RSSI = -103)
  [7] "" (F8:B2:3F:43:6E:F3, RSSI = -100)
  [8] "oura_0_E32000D86085" (E3:20:00:D8:60:85, RSSI = -84)

Select a device to sniff, or '0' to scan again
> 1
Attempting to follow device 00:22:D0:2A:E4:A3
Pipe ready, run: wireshark -Y btle -k -i /Users/jacobrosenthal/Downloads/Adafruit_BLESniffer_Python/logs/ble.pipe
connected: False, packets: 2695, missed: 0