Refactor attach loop device in pure Go
Move attach loop device to its own file
Extract ioctl from wrapper
Check if the target loopback is a block device
Merge branch 'master' into refactor_cgo_in_go
Rename file for consistency
Correct comments
Improve devmapper unit tests with syscall/ioctl
Merge pull request #2923 from creack/refactor_cgo_in_go

Refactor attach loop device in pure Go