Add code to compile _strdup on non-Microsoft platforms (builds on Windows with DevStudio and Cygwin).
Add code to compile _strdup on non-Microsoft platforms (builds on Windows with DevStudio and Cygwin).

kamilzubair/ChaiScript,lefticus/ChaiScript,kamilzubair/ChaiScript,bradparks/ChaiScript__cplusplus_scripting_language,kamilzubair/ChaiScript,lefticus/ChaiScript,lefticus/ChaiScript,bradparks/ChaiScript__cplusplus_scripting_language,bradparks/ChaiScript__cplusplus_scripting_language