dev environment setup instruction updated for osx
dev environment setup instruction updated for osx

ColossusCoinXT/ColossusCoinXT,ColossusCoinXT/ColossusCoinXT,ColossusCoinXT/ColossusCoinXT,ColossusCoinXT/ColossusCoinXT,ColossusCoinXT/ColossusCoinXT,ColossusCoinXT/ColossusCoinXT