Fixes for log tailing
Fixes for log tailing

IN_ATTRIB inotify events are generated when atime / mtime is changed,
which would cause the tail to be reset, and reread the same log
again (generating duplicate events). Instead, watch the directory for
file delete / move.

Also, use an exponential backoff when retrying opening the file.

erSitzt/cadvisor,BrickXu/cadvisor,dchen1107/cadvisor,f0/cadvisor,BrickXu/cadvisor,derekwaynecarr/cadvisor,erSitzt/cadvisor,derekwaynecarr/cadvisor,erSitzt/cadvisor,jhjeong-kr/cadvisor,f0/cadvisor,dchen1107/cadvisor,linux-on-ibm-z/cadvisor,linux-on-ibm-z/cadvisor,jhjeong-kr/cadvisor,f0/cadvisor,linux-on-ibm-z/cadvisor,derekwaynecarr/cadvisor,jhjeong-kr/cadvisor,derekwaynecarr/cadvisor,f0/cadvisor,BrickXu/cadvisor,ncdc/cadvisor,ncdc/cadvisor,ncdc/cadvisor,erSitzt/cadvisor,jhjeong-kr/cadvisor,dchen1107/cadvisor,erSitzt/cadvisor,dchen1107/cadvisor,BrickXu/cadvisor,ncdc/cadvisor,ncdc/cadvisor,jhjeong-kr/cadvisor,dchen1107/cadvisor,derekwaynecarr/cadvisor,f0/cadvisor,BrickXu/cadvisor