[ZEPPELIN-97][ZEPPELIN-134] pyspark issue with mllib api

[Leemoonsoo]

There were issue ZEPPELIN-97 with pyspark 1.4. The reason is, from pyspark 1.4, java gateway is created with auto_convert = True option. This PR fixes the problem.

This PR also handles ZEPPELIN-134, inject sqlContext.

And it finally improves to print more verbose stacktrace message, for example

from

(<type 'exceptions.AttributeError'>, AttributeError("'list' object has no attribute '_get_object_id'",), <traceback object at 0x392b638>)

to

Traceback (most recent call last):
  File "/var/folders/zt/nd4j13y14jjg7_5pc4xgy7t80000gn/T//zeppelin_pyspark.py", line 110, in <module>
    eval(compiledCode)
  File "<string>", line 3, in <module>
  File "/Users/moon/Projects/zeppelin/spark-1.4.0-bin-hadoop2.3/python/pyspark/sql/dataframe.py", line 1200, in withColumn
    return self.select('*', col.alias(colName))
  File "/Users/moon/Projects/zeppelin/spark-1.4.0-bin-hadoop2.3/python/pyspark/sql/dataframe.py", line 738, in select
    jdf = self._jdf.select(self._jcols(*cols))
  File "/Users/moon/Projects/zeppelin/spark-1.4.0-bin-hadoop2.3/python/pyspark/sql/dataframe.py", line 630, in _jcols
    return self._jseq(cols, _to_java_column)
  File "/Users/moon/Projects/zeppelin/spark-1.4.0-bin-hadoop2.3/python/pyspark/sql/dataframe.py", line 617, in _jseq
    return _to_seq(self.sql_ctx._sc, cols, converter)
  File "/Users/moon/Projects/zeppelin/spark-1.4.0-bin-hadoop2.3/python/pyspark/sql/column.py", line 60, in _to_seq
    return sc._jvm.PythonUtils.toSeq(cols)
  File "/Users/moon/Projects/zeppelin/spark-1.4.0-bin-hadoop2.3/python/lib/py4j-0.8.2.1-src.zip/py4j/java_gateway.py", line 529, in __call__
    [get_command_part(arg, self.pool) for arg in new_args])
  File "/Users/moon/Projects/zeppelin/spark-1.4.0-bin-hadoop2.3/python/lib/py4j-0.8.2.1-src.zip/py4j/protocol.py", line 265, in get_command_part
    command_part = REFERENCE_TYPE + parameter._get_object_id()
AttributeError: 'list' object has no attribute '_get_object_id'

[Leemoonsoo]

Ready to merge.

[felixcheung]

LGTM