avreal32 and lock bits

I feel dumb. I was expecting to see AVR's lock bits LB1 and LB2 amongst FUSES in avreal32 programmer, so I never saw that there is a dedicated option for preventing the readback of the chip content.

The command for locking an ATmega168 is (add your usual programmer definition and options):

avreal32 +mega168 -l2 (programmer parameters)

Neat.