Increase font size in Editor
Show maximum file size when upload
Implement feature material is derived other material
Merge branch 'fix_bugs_from_aminh' of https://github.com/voer-platform/vpw

# By Luong Trieu (6) and Zniper (1)
# Via Luong Trieu (3) and luongtd (3)
* 'fix_bugs_from_aminh' of https://github.com/voer-platform/vpw:
  update message help
  Correct displaying of material cover
  fix some bug from feedback of mr.Cuong
  revert code
  fixbug rating material
  fixbug rating material
  fixbug rating material

Conflicts:
	templates/frontend/collection/edit_collection.html
	templates/frontend/module/create_step2.html
	templates/frontend/module/create_step3.html
	templates/frontend/module/edit_module.html