simplify initialization of commands with macro

Issue: Original enumeration constants are uppercase, it seens that _name
       does not convert my lowercase into uppercase. Thus, enumeration
       constants are adjusted into lowercase in name part of commands.

References:
[1] http://gcc.gnu.org/onlinedocs/cpp/Stringification.html
[2] http://stackoverflow.com/questions/216875/in-macros/216912