Refactoring; Ensure SW 5.2 compatibility

Merge pull request #24 in PLUG_OPEN/frontend_swagcustomsort from hack…

…-time/refactoring-improvements to master

* commit '7fefb2220517bb3783042331a39e8e65944eb4ec':
  Fix code style; Improve code; Rename article occurences to product
  Add composer.json
  Add cs-fixer and fix code style

1.0.4

1.0.4

1.0.3

PT-4076 - implement update method to prevent calling of install metho…

…d on plugin update

1.0.2

PT-3998 - prepare plugin.json for store update

1.0.1

PT-3324: prepared plugin.json for store update

1.0.0

PT-2775: code clean up; prepare plugin.json for store update