add sc = init_nncontext() in anomaly-detection (#599)
add sc = init_nncontext() in anomaly-detection (#599)

* add init_engine()

* add init_engine()

* change init_engine() into init_nncontext

* add init_nncontext()

* add init_nncontext()

* add init_nncontext()

* add init_nncontext()

* add import

* change the directory in run-app-test.sh

* add init_nncontext() in sentiment-analysis

* add init_nncontext() in tfnet

* add init_nncontext() in variational autoencoder

* fix minor problems

* fix minor problems

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