Remove the 0.14.x branch (and potentially replace it with a tag on master)

[gu0keno0]

As we discussed online, it will be convenient for us to replace the current 0.14.x branch with a tag on master branch. I created a script to help compare all the commits between 0.14.x and master since the diverging point, and generated a report:

v014x-verify-report.html
verify-v014x-branch.sh

I've went through the report, all commits in 0.14.x should already have been ported to master. So we should be good to go. cc: @LucioFranco @hermeGarcia