Guide: rTorrent + ruTorrent installation

[koper89]

UPDATES:
28.01.14 - Added /etc/default/rtorrent it's the same as couchpotato file where you can ENABLE/DISABLE rtorrent, set NICELEVEL, and change directory for rtorrent config file.
28.01.14 - Uploaded file for new hosting, root access is not needed now (i suppouse, i'll check that when I'll be back from work)
28.01.14 - BUG fixed, works like a charm now

KNOWN BUGS:
- Sometimes this is happening when installing whole package E: dpkg was interrupted, you must manually run 'sudo dpkg --configure -a' to correct the problem.
(fixed by looping whole process, if the error occurs )

TO DO:
- set php5-fpm an nginx max working processes
- add more options on rtorrent config to set
- fully test it on more than 1 device