Changed last-child to first-child
As noted by @jerem the first child will actually be the last shown
replace js scrollspy test for default behavior
add "focus" to focused btns with button plugin
Allow tabs to fade in if no initially active pane is present; fixes #13814
Add a few more cases to the visual test tab page
assign background to row of .table-striped

if background is not set on row, striping doesn't work properly in responsive tables where row and cells are set to  display: block.
removing redundant background declarations on TDs
Added @gray-base variable to make @gray-{shade} reference, also allows @gray-base to be modified with less#modifyVars and the vars to cascade
Fixed @gray-base value being once space short
docs: use valid JSON in compound option value examples

Fixes #13874.
[skip sauce]
Use mousedown instead of click for backdrop click detection; fixes #13816
Only close modal if escape was hit with keydown; fixes #13929
place feedback icon lower, only if it really need
Documents radio and checkbox validation states

References #14010

fixing duped IDs

fix ALL the duped IDs.

make example id match actual id
Moves checkbox/radios into "Validation states" example.
possible fix for #14013
Add collapsed default class to navbar-toggle
clarify the iOS virtual keyboard bug with respect to navbars
fix up examples
Merge branch 'pr/14011'