Create helpers.py revised

All the updating is completely done in here for items, for brands it should be relatively easy now
I have left all the confidence updating for later(commented out for now)
Still need to modularize everything properly, also might have to make itemgraph and brandgraph global variables either inside this or graph.py or events.py 
what do you think?
Merge pull request #8 from samighoche/patch-7

Create helpers.py revised