if hash_count == 0; reinit avalon, fix the 0MHS bug
use the max value of temp1 and temp2 for fan control
for some reason network down. one simple cgminer command:
  "cgminer -o 127.0.0.1:8888 -O fa:ke --avalon-options 115200:32:10:50:256"
can idle the avalon for safe power and protect chip
fix the fan control on max temp2/3
Merge pull request #421 from BitSyncom/avalon

Avalon