Changes in example ns according to issue bbatsov#64

According to conversation in issue bbatsov#64 there is better to use [] in ns declaration after
special forms (:require, :use) since it's clearly describes data. I think same can be
applied to :import and any other form in ns macro.

I think both forms (short and long) are ok to use in real code.

Short form:

```Clojure
(:require [clojure [string :refer :all]
                   [xml :refer :all]])
```

Long form:

```Clojure
(:require [clojure.string :refer :all]]
          [clojure.xml :refer :all]])
```

Author: Gonzih

Diff for: README.md

@@ -253,14 +253,17 @@ pairwise constructs as found in e.g. `let` and `cond`.
     ```Clojure
     (ns examples.ns
       (:refer-clojure :exclude [next replace remove])
-      (:require (clojure [string :as string]
-                         [set :as set])
-                [clojure.java.shell :as sh])
-      (:use (clojure zip xml))
+      (:require [clojure [string :as string
+                                 :refer [blank?]]
+                         [set :as set]]
+                [clojure.java.shell :as sh]
+                [cascalog.api :refer :all]
+                [cascalog.ops :as c])
+      (:use [clojure xml zip])
       (:import java.util.Date
                java.text.SimpleDateFormat
-               (java.util.concurrent Executors
-                                     LinkedBlockingQueue)))
+               [java.util.concurrent Executors
+                                     LinkedBlockingQueue]))
     ```
 
 * Avoid single-segment namespaces.