[Fixes #163] If running processProductImport in batches it creates duplicate options for multi select attributes.
[Fixes #161] Added missing validate method
[Fixes #157] You can now import the country_of_manufacture by their index ID.

Instead of trying to import the full country name like 'Germany', you can now import 'de'
Temporary fix for missing attributes added, stop throwing exception. #151
Fixes #142, Use the default attribute_set_id instead of 0
#118 Better comments for the configuration
Merge branch 'master' into develop
Added increment_id to importable customer fields
Fixed inconsistent use of Dryrun vs DryRun
Made dry run code consistent with the normal import code.
Fixed setting wrong default value for disablePreprocessImageData.
Merge pull request #183 from hostep/dryrunfixes

Dry run fixes
[FEATURE] Added compatibility for EE url_key generation