change skew(x,y) to skewX skewY because mdn told me so
fixes #13346: add a variable for .dl-horizontal's offset
Fixes #13400, #13415: actually document the existing practice for links in panel headings
grunt
Merge pull request #13860 from twbs/fixes_13346

Add a variable for .dl-horizontal's offset
Merge branch 'master' of github.com:twbs/bootstrap
grunt
Merge pull request #13859 from twbs/skew_you

Change skew(x,y) to skewX skewY
Merge branch 'master' into new_striped_progress_bar_class
rewrite striped and active to deprecate the parent selectors, change the docs