add coding style guideline
fix diagd test complile bug
add pci command

Change-Id: I75508e8f447da40a90a24a9c88a2b74f6458560f
Reviewed-on: http://10.208.24.69:8080/52
Reviewed-by: Xudong Huang <xudongh@juniper.net>
Merge branch 'master' into windows