fixes #9807
Merge branch '3.0.0-wip' of github.com:twbs/bootstrap into 3.0.0-wip
Refactor alerts to have a base class, but no default class, thus requiring a modifier class at all times
update theme to match
Update var in theme
Merge pull request #9818 from twbs/bs3_alert_base_class

BS3: Refactor alerts to require a modifier class
Merge branch '3.0.0-wip' into bs3_panel_base_class

Conflicts:
	dist/css/bootstrap-theme.min.css
	dist/css/bootstrap.min.css