Issue #18: Solves issue #18 

+ see https://github.com/emanwebdev/open-eshop/commit/4ec7c075f79e4de4333cd98032e7fdf65001840f
Merge pull request #865 from emanwebdev/#18

Issue #18: Solves issue #18
Merge pull request #866 from oliverds/master

Icons for categories. General settings, move settings to advertisement
working on #151
closes #151
working on #665
working on #665
Saving advertisements settings deletes fields config (#867)
remove icons for categories with glyphicon or font-awesome.
remove icons for categories with glyphicon or font-awesome.
working on #665