build: add options to builder prune

This patch adds --filter, --keep-storage, --all and --force to builder prune.

Signed-off-by: Tibor Vass <tibor@docker.com>

vendor/github.com/docker/docker/api/types/types.go

@@ -543,6 +543,7 @@ type ImagesPruneReport struct {
 // BuildCachePruneReport contains the response for Engine API:
 // POST "/build/prune"
 type BuildCachePruneReport struct {
+	CachesDeleted  []string
 	SpaceReclaimed uint64
 }
 
@@ -592,14 +593,21 @@ type BuildResult struct {
 
 // BuildCache contains information about a build cache record
 type BuildCache struct {
-	ID      string
-	Mutable bool
-	InUse   bool
-	Size    int64
-
+	ID          string
+	Parent      string
+	Type        string
+	Description string
+	InUse       bool
+	Shared      bool
+	Size        int64
 	CreatedAt   time.Time
 	LastUsedAt  *time.Time
 	UsageCount  int
-	Parent      string
-	Description string
+}
+
+// BuildCachePruneOptions hold parameters to prune the build cache
+type BuildCachePruneOptions struct {
+	All         bool
+	KeepStorage int64
+	Filters     filters.Args
 }