distroname: output the distribution name of the system.

Seems that lsb_release -d stops on LSB compliant distributions, the names says all. "distroname" will no stop on LSB compliant distributions and will output the distribution name of all the distribution that could output it. To obtain this goal, it will work on demand, some user wants the output of his distribution, test distroname, if it's not found then
the user and the mantainer can have a way to get the distribution name from the system and add it to the code of distroname.
