Adding import method for type IMPORT_TYPE_CATEGORY_PRODUCT to map a product to n categories
Refactored _import* methods; removed duplicated code
Update documentation
Merge remote-tracking branch 'upstream/master' into catalog_category_product

* upstream/master:
Changed typo from "condig" to "config"
Merge pull request #15 from Zookal/catalog_category_product

[FEATURE] Catalog category product import
Merge pull request #16 from KoenRijpstra/master

Changed typo from "condig" to "config"
[~BUGFIX] Disable the inline translator when operating through cli