Match order of vars to order of components; darken some alert borders
fixes #10526: Remove custom background on responsive tables and set it in the docs where it should've been originally
add .control* to migration docs; fixes #10532
Merge pull request #10542 from twbs/controls-migration-docs

add .control* to migration docs; fixes #10532
Merge branch 'master' of https://github.com/twbs/bootstrap into develop