Revert "Merge pull request #8 from gwtnb/libc++"

This reverts commit 99c40d46a98db25ab49708ebc000655f8a831cc7, reversing
changes made to 01ba9598f14e9a679d31f343b003b36153df55e6.

Commit 99c40d46a98db25ab49708ebc000655f8a831cc7 breaks Jubatus build.