Merge pull request #144 from sfmailand/sbl-dev

Merging from #127
Manually merged Pull request #141 of sfmailand

- Only shwo backlog requirement
Made add/remove buttons uniform

Central add/remove buttons are now uniform over any window size/resolution
Merge pull request #145 from hlong290494/sbl-dev

Manually merged Pull request #141 of sfmailand
Merge pull request #146 from ZPak/sbl-dev

Made add/remove buttons uniform
Remove unused imports