title: Space in String argument is not parsed by args4j
body: <p>I'm trying to pass a text/String parameter to my java tool from Jenkins which is a String containing all sorts of characters.</p>
  
  <p>When the args4j option parses the flag then it only considers the first word and as soon as it hits the second word(after space) it starts throwing an exception. </p>
  
  <p>here's a snippet</p>
  
  <pre><code>@Option(name = "-data_string", usage = "Data")
   private String dataString;
  </code></pre>
  
  <p>When I pass argument as -data_string="This is a test" then I get Exception </p>
  
  <pre><code>Exception in thread "main" java.lang.reflect.InvocationTargetException
  at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
  at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
  at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
  at java.lang.reflect.Method.invoke(Method.java:498)
  at org.eclipse.jdt.internal.jarinjarloader.JarRsrcLoader.main(JarRsrcLoader.java:58)Caused by: org.kohsuke.args4j.CmdLineException: "-data_string=This is a test" is not a valid option
  at org.kohsuke.args4j.CmdLineParser.parseArgument(CmdLineParser.java:512)
  at scraper.client.ScraperClient.main(ScraperClient.java:28)
  ... 5 more
  </code></pre>
  
  <p>Please suggest.</p>