Merge pull request #162 from ssushma/release-6.2

Hiding the Thumbnail URL tag from the info tab in resource player
Merge pull request #163 from ssushma/release-6.2

Recent changes for Teacher tip disappears once the user shifts tab and c...
Merge pull request #165 from ssushma/release-6.2

Study tab Classlist not refreshing on Join class button click on Join cl...
Added absolute top to the tooltip in the add button on resource page
Merge pull request #167 from chandrasekharv/release-6.2

Added absolute top to the tooltip in the add button on resource page
Firefox: At organize level all the default gooru images for collections are broken. - Resolved