Use eager loading in material seen count traking to imporve performence
Merge remote-tracking branch 'upstream/development' into features/material-eager-loading
Merge pull request #251 from wangqiang1208/features/material-eager-loading

Material eager loading
Connect marketplace and lecturer request function. Add redirect option to role_request pages.
Merge branch 'development' of https://github.com/Coursemology/coursemology.org into marketplace