Mention that this htop fork is outdated

Added link to original htop project, where there's an ongoing campaign to add Mac OS X support in htop 1.x.
http://hisham.hm/htop/

https://www.bountysource.com/teams/htop/fundraiser
Merge pull request #15 from joelpurra/patch-1

Mention that this htop fork is outdated