Broken on OS X Mavericks

[benedictpaten]

Seems like they finally switched fully from GCC to Clang in OS X Mavericks.

I got Sonlib/cactus to build by adding:

ifeq (${SYS},Darwin) #This is to deal with the Mavericks replacing gcc with clang fully
cxx = clang -std=c99 -stdlib=libstdc++
cpp = clang++ -stdlib=libstdc++
done

(You don't have to call it clang, you can still refer to gcc, but it makes no difference).

The important flag was -stdlib=libstdc++, which makes it use the older standard library.

See: Homebrew/legacy-homebrew#23308

But, I couldn't fix mafTools so easily - clang complains that you use -lm flag unnecessarily in linking. Probably can be avoided by not using strict compile checking.

[benedictpaten]

PS, SYS = $(shell uname -s)