Allow additional arguments to be passed into hooks

If a packager wants to be able to support addititional arguments on his
hook this will allow them to setup the configuration with these arguments.

For example this would allow a hook developer to add support for a --debug
flag to change the level of debugging in his hook.

In order to complete this task, I had to vendor in the latest
github.com://opencontainers/runtime-tools, which caused me to have to fix a
Mount and Capability interface calls

Signed-off-by: Daniel J Walsh <dwalsh@redhat.com>

vendor/github.com/opencontainers/runtime-tools/filepath/ancestor.go

@@ -0,0 +1,32 @@
+package filepath
+
+import (
+	"fmt"
+	"strings"
+)
+
+// IsAncestor returns true when pathB is an strict ancestor of pathA,
+// and false where the paths are equal or pathB is outside of pathA.
+// Paths that are not absolute will be made absolute with Abs.
+func IsAncestor(os, pathA, pathB, cwd string) (_ bool, err error) {
+	if pathA == pathB {
+		return false, nil
+	}
+
+	pathA, err = Abs(os, pathA, cwd)
+	if err != nil {
+		return false, err
+	}
+	pathB, err = Abs(os, pathB, cwd)
+	if err != nil {
+		return false, err
+	}
+	sep := Separator(os)
+	if !strings.HasSuffix(pathA, string(sep)) {
+		pathA = fmt.Sprintf("%s%c", pathA, sep)
+	}
+	if pathA == pathB {
+		return false, nil
+	}
+	return strings.HasPrefix(pathB, pathA), nil
+}