[CMake] FindOpenThreads

[Pau Garcia i Quiles]

Hello,

I was to write a FindOpenThreads.cmake (which I will submit for  
inclussion in the next CMake version) when the doubt assailted me:  
should I patch FindThreads.cmake or write a new, independent package?

(I think the latter makes more sense, as they are not an operating  
system "stock" library)

-- 
Pau Garcia i Quiles
http://www.elpauer.org
(Due to the amount of work, I usually need 10 days to answer)