fixed tokenization of e.g. 'N=100'

previous regex hack wasn’t working for annotated text (was not spotting
‘N=<n>100</n>’
deleted bilearn_rf.py

not needed any more
able to retrieve abstracts by biviewer id

new function added to LabeledAbstractReader to allow it to be used by
bilearn.py
stop commiting CNLP.INI