This patch takes all the HostUtil functionality currently found in
mount*.go files and copies it into hostutil*.go files. Care was taken to
preserve git history to the fullest extent.
As part of doing this, some common functionality was moved into
mount_helper files in preperation for HostUtils to stay in k/k and Mount
to move out. THe tests for each relevant function were moved to test
files to match the appropriate location.
fix log warning
use IsCorruptedMnt in GetMountRefs on Windows
use errorno in IsCorruptedMnt check
fix comments: add more error code
add more error no checking
change year
fix comments
