[WIP] Refactor/rename product attribute

Bug fix: [no]
Feature addition: [no]
Backwards compatibility break: [yes]
Unit test passes: [yes]
Behat scenarios passes: [yes]
Checkstyle issues: [no]
ChangeLog updated: [yes]
Doc PR : https://github.com/akeneo/pim-docs/pull/11
Related PR : https://github.com/akeneo/IcecatDemoBundle/pull/3
Fixes the following jira: PIM-1813