Add VMware Horizon plugin

[themaxdavitt]

Wanted to wait for feedback on my other PR first (since again, I'm pretty new to this), but this plugin development experience has been pretty smooth and easy so far, so I decided to try my hand at making my own plugin also. I'd love to know what you guys think about it!

[urbanadventurer]

Very cool @themaxdavitt 😎 I especially like the aggressive match to get the exact version number from /portal/info.jsp.

[themaxdavitt]

Thanks! :)