Support list within a list for kerasNet forward (#515)
Support list within a list for kerasNet forward (#515)

* support table in a table

* support forward

intel-analytics/BigDL,yangw1234/BigDL,intel-analytics/BigDL,yangw1234/BigDL,yangw1234/BigDL,yangw1234/BigDL,intel-analytics/BigDL,intel-analytics/BigDL