SSL + arguments + python3 + skip collectors

[jweyrich]

Hi,

First, I'd like to thank you because your project is quite handy for us (@teltec). Second, I implemented a few extra things we needed, so I'd would like to contribute back ;-)

• Support SSL connection to Zabbix server using client certificate - Requires Python>=2.7.9 (introduced SSLContext);
• Make script compatible with Python 3;
• Add support for arguments;
• Add support to skip a data collector;

NOTE: I didn't update the README though :/ I'll try in my spare time.

Please, let me know if you find any problem(s) or have any concerns.