Being able to override the process_name in the procstat module
is useful for daemonized perl, ruby, erlang etc. processes. This
allows for manually setting process_name rather than it being set to
the interpreter/VM of the process.
This will basically make the root directory a place for storing the
major telegraf interfaces, which will make telegraf's godoc looks quite
a bit nicer. And make it easier for contributors to lookup the few data
types that they actually care about.
closes#564
Rikaard Hosein
Cameron Sparr
Jared Biel
Thibault Cohen
Jack Zampolin