Add support Streamlink (replace livestreamer)

[thejustsoul]

If possible add support Streamlink, this is a replacement for Livestreamer (it seems abandoned, long time no updates).

UPD: Streamlink-Portable

[tl-pierre]

I put the path of streamlink instead of livestreamer and it works (/usr/local/bin/streamlink for me on Mint 18.1). I think you can update the description of TwitchFox on the mozilla addons website !

[thejustsoul]

A small guide for those who want to make and use a portable Streamlink (v0.3.0+) with Twitch-Fox:

1. Download installer from https://github.com/streamlink/streamlink/releases/download/0.3.0/streamlink-0.3.0.exe
2. Unpack streamlink-0.3.0.exe, using 7-zip (as a regular archive) in the right folder
3. Edit file bin\streamlink-script.py, replace the first line to #!Python\python, save
4. Copy file $APPDATA\streamlink\streamlinkrc to Streamlink folder
5. Edit file streamlinkrc, find and replace options:

   rtmpdump=rtmpdump\rtmpdump.exe
   ffmpeg-ffmpeg=ffmpeg\ffmpeg.exe

6. Create in the Streamlink folder a batch file, ex.: streamlink.bat, with the code:

   @echo off
   setlocal
   set PATH="%~dp0bin"
   pushd "%~dp0"
   streamlink.exe --config "%~dp0streamlinkrc" %*
   popd
   exit /B

7. In the settings Twitch-Fox, specify path to this batch as path for livestreamer
8. Can remove folder $APPDATA and $PLUGINSDIR, they are not needed
9. Done.

If you don't want to make portable Streamlink:

1. Simply install the application (streamlink-0.3.0.exe)
2. Specify full path to streamlink.exe, ex.: C:\Program Files (x86)\Streamlink\bin\streamlink.exe in the settings Twitch-Fox
3. Done.

I hope it will be useful to someone.