add -Wsequence-point flag to C(clang) makefile
add -Wsequence-point flag to C(clang) makefile

cyber-dojo/web,cyber-dojo/web,byran/cyber-dojo-web,cyber-dojo/web,byran/cyber-dojo-web,byran/cyber-dojo-web,byran/cyber-dojo-web,byran/cyber-dojo-web,byran/cyber-dojo-web,cyber-dojo/web,byran/cyber-dojo-web,byran/cyber-dojo-web,byran/cyber-dojo-web