network: support network isolate

Add new crd to convert kubesphere network policy to k8s network policy, and then other network
plugin will do the rest work.

Use  cache.go from calico project's kube-controller,  it aim to  sync nsnp with k8s np, delete unused np, and relieve the pressure on k8s restful client.

If you want higher performance, you can implement interface  NsNetworkPolicyProvider in pkg/controller/provider/namespace_np.go.

Signed-off-by: Duan Jiong <djduanjiong@gmail.com>

vendor/github.com/patrickmn/go-cache/README.md

@@ -0,0 +1,83 @@
+# go-cache
+
+go-cache is an in-memory key:value store/cache similar to memcached that is
+suitable for applications running on a single machine. Its major advantage is
+that, being essentially a thread-safe `map[string]interface{}` with expiration
+times, it doesn't need to serialize or transmit its contents over the network.
+
+Any object can be stored, for a given duration or forever, and the cache can be
+safely used by multiple goroutines.
+
+Although go-cache isn't meant to be used as a persistent datastore, the entire
+cache can be saved to and loaded from a file (using `c.Items()` to retrieve the
+items map to serialize, and `NewFrom()` to create a cache from a deserialized
+one) to recover from downtime quickly. (See the docs for `NewFrom()` for caveats.)
+
+### Installation
+
+`go get github.com/patrickmn/go-cache`
+
+### Usage
+
+```go
+import (
+	"fmt"
+	"github.com/patrickmn/go-cache"
+	"time"
+)
+
+func main() {
+	// Create a cache with a default expiration time of 5 minutes, and which
+	// purges expired items every 10 minutes
+	c := cache.New(5*time.Minute, 10*time.Minute)
+
+	// Set the value of the key "foo" to "bar", with the default expiration time
+	c.Set("foo", "bar", cache.DefaultExpiration)
+
+	// Set the value of the key "baz" to 42, with no expiration time
+	// (the item won't be removed until it is re-set, or removed using
+	// c.Delete("baz")
+	c.Set("baz", 42, cache.NoExpiration)
+
+	// Get the string associated with the key "foo" from the cache
+	foo, found := c.Get("foo")
+	if found {
+		fmt.Println(foo)
+	}
+
+	// Since Go is statically typed, and cache values can be anything, type
+	// assertion is needed when values are being passed to functions that don't
+	// take arbitrary types, (i.e. interface{}). The simplest way to do this for
+	// values which will only be used once--e.g. for passing to another
+	// function--is:
+	foo, found := c.Get("foo")
+	if found {
+		MyFunction(foo.(string))
+	}
+
+	// This gets tedious if the value is used several times in the same function.
+	// You might do either of the following instead:
+	if x, found := c.Get("foo"); found {
+		foo := x.(string)
+		// ...
+	}
+	// or
+	var foo string
+	if x, found := c.Get("foo"); found {
+		foo = x.(string)
+	}
+	// ...
+	// foo can then be passed around freely as a string
+
+	// Want performance? Store pointers!
+	c.Set("foo", &MyStruct, cache.DefaultExpiration)
+	if x, found := c.Get("foo"); found {
+		foo := x.(*MyStruct)
+			// ...
+	}
+}
+```
+
+### Reference
+
+`godoc` or [http://godoc.org/github.com/patrickmn/go-cache](http://godoc.org/github.com/patrickmn/go-cache)