Check if nav has the sticky class before adding or removing it. Not checking causes severe framerate drops as addClass was called continuously during page scroll.
Merge pull request #3080 from rvinay88/master

Remove emCalc from topbar breakpoint
remove duplicate code
aloks change to variables.scss, -margin-bottom set to 0
Merge branch 'master' of github.com:zurb/foundation
Merge pull request #3059 from olafurnielsen/master

Check if sticky nav has the fixed class before adding or removing it.
Made  display: block important. Fixes issue with using jquery show on error labels.
Merge pull request #3093 from VoiceOfWisdom/important-error

Made  display: block important. Fixes issue with using jquery show on error messages