Replace deprecated uses of .pull-left & .pull-right in .media docs

BS3 commits: 88dfd954fa8b0eeefe37482ffd1dba19b1369098
Revert "Use jsDelivr CDN until BootstrapCDN gets updated"

BS3 commits: 505171ef5d127e0e9a4ec82641396fd43804ace4
Customizer: listen to the right event for manual file selection in import

BS3 commits: 12b3ba72787eedec75edd0af7c01616184930068
Add Wall of Browser Bugs entry for 14409

BS3 commits: 4613b366316649ed864d1443605a1e597aecf8d0
Cover common contributor mistakes in CONTRIBUTING.md

BS3 commits: 9a37a937a646ce8a388ab386121a07f98c7e5425
Examples: Make use of the `footer` tag instead of a class.

BS3 commits: 15faedd8349ef537110351716d6a18ac8dbb6969
Update Jekyll to v2.4.0 and rouge to v1.7.2.

BS3 commits: 7d8bacb8178c33c389575d1fc0fc2d99590eb4b6
fix whitespace in js dropdown docs

BS3 commits: 947aa1f7e422a65d12ae92a05c9c7a313ea930af
Fix typo

BS3 commits: ab6f79c472bc306c82f85dea660e7c7351e3413e
Add Wall of Browser Bugs entry for 14972

BS3 commits: 17a6b5e8432fe38397be01e8e79d473b8b84d77f
Add 14868 to the compatibility docs

BS3 commits: f0d8894d54afbd10b43a0919383b35fdbf961b51
Add event.relatedTarget + `data-*` example to Modal docs

BS3 commits: 594831f4f3f3c1164812cfdd60497fe6d7438376
Use Jekyll data for Wall of Browser Bugs

BS3 commits: 069488dea398fa6124602e43ae633fe4781a4837
Remove duplicate code from Customizer/Gruntfile by sharing it

BS3 commits: d10700427805c40497b24d7f4ffdd58a7a83c997
Use autoprefixer for Customizer builds

BS3 commits: d6a99cb95534914655af462af023433c86c437ec
Add initialization examples to tooltip and popover "Opt-in functionality" callouts

BS3 commits: e55feacf5be152694205b14491ad626537756314
Deprecate diagonal tooltip classes

BS3 commits: da3870feacc64c337f4b298a79cb115d9fbb4194
grunt

BS3 commits: 6020bb06f242450b34a55e6098e9549f33fcc226
Use a Jekyll plugin instead of the `copy:configBridge` grunt task

BS3 commits: 03834866654025396530e5c4dddcd74cd214db30
Customizer: Remove file type check from config import

BS3 commits: d77546963b823629c86fcbec949d9fd895fc0922