Merge pull request #160 from chandrasekharv/release-6.2

Auto pagination implemented for library lessons when the overall widget count < 15 to prevent scroll disabling.
Hiding the Thumbnail URL tag from the info tab in resorce and preview player.
Merge pull request #162 from ssushma/release-6.2

Hiding the Thumbnail URL tag from the info tab in resource player
Recent changes for Teacher tip disappears once the user shifts tab and come back to share tab - this issue is resolved.
Merge pull request #163 from ssushma/release-6.2

Recent changes for Teacher tip disappears once the user shifts tab and c...
Study tab Classlist not refreshing on Join class button click on Join class popup.
Merge pull request #165 from ssushma/release-6.2

Study tab Classlist not refreshing on Join class button click on Join cl...