fix overflowing text from ps by swapping args for comm

[dch]

Instead of sending full arguments list of process output, only send the command name.

fixes #16

On systems with multiple daemons and complex command lines running, it seems riemann-tools gets confused. There might be an underlying issue that causes UDP overflow, but this workaround seems sensible anyway.

• works on OSX
• works on ubuntu precise
• probably works on all reasonable unixes

On http://unixhelp.ed.ac.uk/CGI/man-cgi?ps find comm for what changed, or man ps.

[aphyr]

I'm up for this; typically args just get in the way. I still need to fix the underlying bug; riemann should automatically switch to TCP for large messages.