deal with security exception when checking for CUDA on Mac. fixes #629
deal with security exception when checking for CUDA on Mac. fixes #629

tgvaughan/beast2,tgvaughan/beast2,Anaphory/beast2,Anaphory/beast2,tgvaughan/beast2,tgvaughan/beast2,Anaphory/beast2,CompEvol/beast2,CompEvol/beast2,CompEvol/beast2,Anaphory/beast2,CompEvol/beast2