Shortend the variables so I could stay in the 80 COL limit more
easily.

Before this commit, the program would just panic if any kind of io
error would occur. Now the program will exit gracefully with
printing the error beforehand.

NOTE:
The program always exits with a exit code of 0, even if an error
occured.

After discussing some changes to the current protocoll we came up
with this stable protocoll v2:
[VER:8][SEQ:8][ID:8 ][RES:8]
[        PIXEL:32*n        ]
[           ...            ]
[           ...            ]

With PIXEL:32 being in this order:
[G  :8][R  :8][B  :8][W  :8]

This led to merging of the two functions as we now only send GRBW.
RGB strips should either discard the W byte or use it's value to
recalculate it's RGB values.

Set default value of leds to zero to prevent screwing up a strip by accidently running the command with wrong paramters.