$2 in up and down. Add Current command useful for script

Hi.
I use your script every day on my laptop.
I've added some features that I think could be interesting. In particular:

pulseaudio-ctl up N  or pulseaudio-ctl up N% for increase volume of N%
Same with "down".
pulseaudio-ctl u or d  (without N) are like before (5%).

"pulseaudio-ctl C|c|[C,c]urrent" simply print the current volume (useful for scripting).

:D