title: ANT SSHEXEC failing with Algorithm negotitation fail error
body: <p>I am just trying to connect to a remote host using the ant sshexec task . I have the required jar in the ant lib directory and able to connect to the remote host using putty.
  This is the way i am running the ssh</p>
  
  <pre><code> &lt;sshexec host="host"
  username="username"
  password="password"
  trust="yes"
  command="ls"/&gt;
  </code></pre>
  
  <p>There seems to be encryption algorith mismatch with the server. How can i specify the algorith as I don't see any attribute for this task [Ant doc][1]. This is the error log i am getting:</p>
  
  <pre><code>com.jcraft.jsch.JSchException: Algorithm negotiation fail
      at com.jcraft.jsch.Session.receive_kexinit(Session.java:540)
      at com.jcraft.jsch.Session.connect(Session.java:288)
      at com.jcraft.jsch.Session.connect(Session.java:145)
      at org.apache.tools.ant.taskdefs.optional.ssh.SSHBase.openSession(SSHBase.java:212)
      at org.apache.tools.ant.taskdefs.optional.ssh.SSHExec.execute(SSHExec.java:158)
      at org.apache.tools.ant.UnknownElement.execute(UnknownElement.java:288)
      at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
      at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
      at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
      at java.lang.reflect.Method.invoke(Method.java:606)
      at org.apache.tools.ant.dispatch.DispatchUtils.execute(DispatchUtils.java:106)
      at org.apache.tools.ant.Task.perform(Task.java:348)
      at org.apache.tools.ant.Target.execute(Target.java:357)
      at org.apache.tools.ant.Target.performTasks(Target.java:385)
      at org.apache.tools.ant.Project.executeSortedTargets(Project.java:1337)
      at org.apache.tools.ant.Project.executeTarget(Project.java:1306)
      at org.apache.tools.ant.helper.DefaultExecutor.executeTargets(DefaultExecutor.java:41)
      at org.apache.tools.ant.Project.executeTargets(Project.java:1189)
      at org.apache.tools.ant.Main.runBuild(Main.java:758)
      at org.apache.tools.ant.Main.startAnt(Main.java:217)
      at org.apache.tools.ant.launch.Launcher.run(Launcher.java:257)
      at org.apache.tools.ant.launch.Launcher.main(Launcher.java:104)
  </code></pre>