add a formula for compiling cryptopp with libstdc++

As described here http://blog.inventic.eu/2014/01/qt-on-osx-maverick-undefined-symbols-for-architecture-x86_64/ you need to compile cryptopp with libstdc++ to include it into a qt project
Can this test be modified to do something more substantial then e.g. `--version` or `--help`? See `cmake.rb` for an example of a formula with a good test. Thanks!