Sync v-4dev with twbs#4

Merged

tmorehouse merged 6 commits intotmorehouse:v4-devfrom

Dec 8, 2017

Commits on Dec 2, 2017

Remove .col-form-legend in favor of .col-form-label (#24932)

tmorehouse
authored and
mdo
committed
Document breaking change from #24932
mdo
committed

Commits on Dec 4, 2017

Update devDependencies and gems. (#24940)
XhmikosR
authored

Commits on Dec 5, 2017

Remove page reload in pwa.js. (#24923)
XhmikosR
authored

Commits on Dec 7, 2017

Use only transitionend event (#24962)

kamlekar
authored and
Johann-S
committed

Commits on Dec 8, 2017

Update link to Font Awesome

coliff
authored and
Johann-S
committed