Switch to new vendor directory layout

Fixes #113

Signed-off-by: Marcos Lilljedahl <marcosnils@gmail.com>

vendor/github.com/opencontainers/runc/libcontainer/cgroups/cgroups.go

@@ -0,0 +1,64 @@
+// +build linux
+
+package cgroups
+
+import (
+	"fmt"
+
+	"github.com/opencontainers/runc/libcontainer/configs"
+)
+
+type Manager interface {
+	// Apply cgroup configuration to the process with the specified pid
+	Apply(pid int) error
+
+	// Returns the PIDs inside the cgroup set
+	GetPids() ([]int, error)
+
+	// Returns the PIDs inside the cgroup set & all sub-cgroups
+	GetAllPids() ([]int, error)
+
+	// Returns statistics for the cgroup set
+	GetStats() (*Stats, error)
+
+	// Toggles the freezer cgroup according with specified state
+	Freeze(state configs.FreezerState) error
+
+	// Destroys the cgroup set
+	Destroy() error
+
+	// NewCgroupManager() and LoadCgroupManager() require following attributes:
+	// 	Paths   map[string]string
+	// 	Cgroups *cgroups.Cgroup
+	// Paths maps cgroup subsystem to path at which it is mounted.
+	// Cgroups specifies specific cgroup settings for the various subsystems
+
+	// Returns cgroup paths to save in a state file and to be able to
+	// restore the object later.
+	GetPaths() map[string]string
+
+	// Set the cgroup as configured.
+	Set(container *configs.Config) error
+}
+
+type NotFoundError struct {
+	Subsystem string
+}
+
+func (e *NotFoundError) Error() string {
+	return fmt.Sprintf("mountpoint for %s not found", e.Subsystem)
+}
+
+func NewNotFoundError(sub string) error {
+	return &NotFoundError{
+		Subsystem: sub,
+	}
+}
+
+func IsNotFound(err error) bool {
+	if err == nil {
+		return false
+	}
+	_, ok := err.(*NotFoundError)
+	return ok
+}