(Windows) Improve Support on Windows Plattform by including winutils.exe and check for HADOOP_HOME

I checked Zeppelin 0.7.1 and 0.8.0-SNAPSHOT on a clean Windows 7 and Windows 10 system (running in VMWare). Both version of Zeppelin show the following behaviour on both systems:

• Zeppelin runs
• md interpreter works
• SPARK interpreter fails with the usual InvocationTargetException

Tracking down the error is hard, but I found that it is related to

• winutils.exe is missing in the distribution
• HADOOP_HOME is not set (needs to point to a directory which contains bin/winutil.exe)

The error does not occure if somebody comes with a preinstalled hadoop (and a well defined HADOOP_HOME). The error does also not occure if zeppelin runs on OS X.

I would suggest to include winuils.exe in zeppelin/bin and add a test of HADOOP_HOME to the interpreter.cmd. If HADOOP_HOME is not set it should be set inside interpreter.cmd.

If OK, I would prepare a pull request. OK?