PIM-1562 : rename csv category reader
PIM-1562 : rename csv product reader
PIM-1562 : rename product reader UT
PIM-1562 : refactor csv reader services
PIM-1562 : refactor abstract entity processor, by default it deals with
one item and not a collection (allow to use with default line per line reader)
PIM-1562 : refactor attribute processor
PIM-1562 : refactor attribute option processor
PIM-1562 : refactor association processor
PIM-1562 : refactor group processor
PIM-1562 : fix csv reader translations
PIM-1562 : update demo bundle ref
Merge pull request #481 from akeneo/PIM-1562

PIM-1562 : refactor to use line per line reader (by default), same idea for processor