Build and install from GOPATH

* Rename 'vendor/src' -> 'vendor'
  * Ignore vendor/ instead of vendor/src/ for lint
* Rename 'cmd/client' -> 'cmd/ocic' to make it 'go install'able
* Rename 'cmd/server' -> 'cmd/ocid' to make it 'go install'able
* Update Makefile to build and install from GOPATH
* Update tests to locate ocid/ocic in GOPATH/bin
* Search for binaries in GOPATH/bin instead of PATH
* Install tools using `go get -u`, so they are updated on each run

Signed-off-by: Jonathan Yu <jawnsy@redhat.com>

vendor/github.com/containers/storage/drivers/aufs/dirs.go

@@ -0,0 +1,64 @@
+// +build linux
+
+package aufs
+
+import (
+	"bufio"
+	"io/ioutil"
+	"os"
+	"path"
+)
+
+// Return all the directories
+func loadIds(root string) ([]string, error) {
+	dirs, err := ioutil.ReadDir(root)
+	if err != nil {
+		return nil, err
+	}
+	out := []string{}
+	for _, d := range dirs {
+		if !d.IsDir() {
+			out = append(out, d.Name())
+		}
+	}
+	return out, nil
+}
+
+// Read the layers file for the current id and return all the
+// layers represented by new lines in the file
+//
+// If there are no lines in the file then the id has no parent
+// and an empty slice is returned.
+func getParentIds(root, id string) ([]string, error) {
+	f, err := os.Open(path.Join(root, "layers", id))
+	if err != nil {
+		return nil, err
+	}
+	defer f.Close()
+
+	out := []string{}
+	s := bufio.NewScanner(f)
+
+	for s.Scan() {
+		if t := s.Text(); t != "" {
+			out = append(out, s.Text())
+		}
+	}
+	return out, s.Err()
+}
+
+func (a *Driver) getMountpoint(id string) string {
+	return path.Join(a.mntPath(), id)
+}
+
+func (a *Driver) mntPath() string {
+	return path.Join(a.rootPath(), "mnt")
+}
+
+func (a *Driver) getDiffPath(id string) string {
+	return path.Join(a.diffPath(), id)
+}
+
+func (a *Driver) diffPath() string {
+	return path.Join(a.rootPath(), "diff")
+}