add missing event namespacing in modal.js
Reassigned minification of CSS to cssmin task.

Reassigned minification of CSS files from the less task to the cssmin
task
Merge pull request #13615 from twbs/namespacing

add missing event namespacing in modal.js
fix typo in assertion description
Merge pull request #13624 from robertdodd/master

Reassigned minification of CSS files to the cssmin task.