Added a third parameter to set the limit, and the behavior is then controled 
by extra options.
// - "minErrorTrain" (stop when NN error on the training sample gets below 
minE
// - "minErrorTest" (stop when NN error on the test sample gets below minE

The limit on epochs is always active but can be put to a high value. This 
guaranties the stopping condition.


git-svn-id: http://root.cern.ch/svn/root/trunk@36832 27541ba8-7e3a-0410-8455-c3a389f83636