Building clang/cling 3.5 for ROOT on Lion

[Chris Jones]

>> PS: It's not an issue of me personally upgrading the OS. I'll do that
>> sooner or later. But it would be slightly suboptimal if the port only
>> worked on 10.9.

As a general point, I agree, only OSX10.9 has full c++11 support. 
However, upstream claim to be targeting 10.8 and 10.9, so I would hope 
it would work on OSX10.8 as well (to be tested sometime, by someone who 
has access to a 10.8 machine). Whilst not ideal, I think this is 
reasonable coverage (given root5 will remain available for all versions).

Chris