added 'window' function to pipelines

now uses a localised bag of words
remove duplicate code

shares feature generation with bilearnPipeline now
second version bilearn

kept separate for the moment, implements weighting but slightly buggy
updates

tidying up
returns HTML of SoF tables

previously returned the text, but since is an HTML table returns a
table now
restrict train and test data to integers

quicker and shouldn’t affect precision, recall, or f particularly;
however, useful to amend later back to compare with other papers which
use per-word accuracy (which looks better!)
ignore log files