ENH:  Started work on vw_helpers
UP: Built the basic LDAResults and started SFileFilter
UP: End of night
UP: Before changing VW format
UP: Before switching all to smart_open
UP: Converted all to smart_open
ADD filter_sfile
UP: Basic setup seems to work
UP: Final (hopefully) changes before PR
Merge branch 'master' into vw-helpers
MERGE: Fixed conflicts