Cpp fixes

To combat the error:

        Error in dyn.load(file, DLLpath = DLLpath, ...) :
          unable to load shared object '/Library/Frameworks/R.framework/Versions/3.0/Resources/library/mungebitsTransformations/libs/mungebitsTransformations.so':
         dlopen(/Library/Frameworks/R.framework/Versions/3.0/Resources/library/mungebitsTransformations/libs/mungebitsTransformations.so, 6): Symbol not found: __ZNK4Rcpp7RObject4attrERKNSt3__112basic_stringIcNS1_11char_traitsIcEENS1_9allocatorIcEEEE

The issue was that osx has two standard libraries, and the wrong one was being included:

https://groups.google.com/forum/#!msg/stan-users/_7Lu0ahphik/ugnqQ0KqsCQJ