Support redirecting jvm output to python process (when using notebook) (#2441)
Support redirecting jvm output to python process (when using notebook) (#2441)

* support redirect jvm output to python process

* add license statement, add doc, refine style

* change to global variable
yangw1234/BigDL,intel-analytics/BigDL,yangw1234/BigDL,intel-analytics/BigDL,intel-analytics/BigDL,yangw1234/BigDL,yangw1234/BigDL,intel-analytics/BigDL