Merge pull request #155 from nutan-gooru/release-6.2

check null condition to display default image
"Handled the question standards while updating by doing refresh"
Merge remote-tracking branch 'upstream/release-6.2' into release-6.2
Merge pull request #156 from suryanarayanakb/release-6.2

Handled the question standards while updating by doing refresh
"Educational info panel hiding and showing changes fixed."
Merge remote-tracking branch 'upstream/release-6.2' into release-6.2
Merge pull request #158 from sravanthi1/release-6.2

"Educational info panel hiding and showing changes fixed."
Auto pagination implemented for library lessons when the overall widget count < 15 to prevent scroll disabling.
Merge remote-tracking branch 'upstream/release-6.2' into release-6.2
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...
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
The Gooru default images folder for profile settings default images.