added initial version of nnet module (revisiting trainers now)
added initial version of nnet module (revisiting trainers now)

zhmz90/hep_ml,iamfullofspam/hep_ml,chrinide/hep_ml,nickcdryan/hep_ml,nickcdryan/hep_ml,anaderi/hep_ml,zhmz90/hep_ml,anaderi/hep_ml,iamfullofspam/hep_ml