fires closed.bs.alert *after* DOM detach()

fires closed.bs.alert *after* element is removed from DOM.
Previously it fired while the element was still attached.
Update alert.js

Added call to remove() after event fires to clean up data as per discussion at #12379
emphasize that bootstrap-rtl.css & bootstrap.css should not be used together
Fix .visible-print deprecation version #.
Allow for resetText of a button to be a falsey value; fixes #13466
Merge pull request #13406 from EnsignR/closed.bs.alert-after-remove

fires closed.bs.alert *after* DOM detach() as per #12379
Merge pull request #13511 from hnrch02/button-reset-falsey-values-fix

Allow for resetText of a button to be a falsey value; fixes #13466
Update JSZip to v2.2.2.
tweak formatting in Carousel docs for clarity; fixes #13522
unlock & bump grunt-jscs-checker to ~0.4.3
Merge pull request #13528 from twbs/unlock-jscs

unlock & bump grunt-jscs-checker to ~0.4.3
Merge pull request #13504 from Quy/resputil

Fix .visible-print deprecation version #.
Merge pull request #13499 from twbs/clarify-rtl

emphasize that bootstrap-rtl.css & bootstrap.css should not be used together
move rtl to getting started, per @cvrebert's feedback
move Grunt info from README into HTML docs

Fixes #13470
Merge pull request #13531 from twbs/grunt-html-docs

move Grunt info from README into HTML docs
Update .travis.yml