quick fix for docs mention
Add role="toolbar" to elements with .btn-toolbar.
fix #9924
fix #9917
CONTRIBUTING: reflect move away from *-wip branch style of development

Per http://blog.getbootstrap.com/2012/12/10/bootstrap-3-plans/ :
> * Drop the `*-wip` branch style of development.
point release download link to an actual release instead of `master`
links to a release instead of master, so rephrase description accordingly
master branch is no longer stationary, so don't imply otherwise
fix #9915
update copyright year
add variables for heading font sizes; fixes #9921
regenerate customizer's raw-files.js
add header font size vars to customizer page
rename @screen-XX to @screen-XX-min for clarity+unambiguity
Added fonts to "main" files

When using bower the "main" property is used to specify the files that should be consumed by applications including the package as a dependency.
Without including the fonts in this array the glyphicons do not work correctly as the relative font paths do not work after the "main" files are copied into my projects public dir using tools like https://github.com/yatskevich/grunt-bower-task

For now I have manually copied the fonts dir in the location needed for my project. But by accepting this pull request this will not be necessary for me or for other people that use bower.
Update justified-nav.css

Removed unnecessary ms-linear-gradient prefix. There was never a stable release of IE that supported -ms- prefixed gradients, those were only in preview versions (stable IE10 supports both prefixed and unprefixed gradients). (source: http://lea.verou.me/2013/04/can-we-get-rid-of-gradient-prefixes/)
Merge pull request #9973 from coliff/patch-6

Update justified-nav.css (Removed unnecessary ms-linear-gradient prefix)
fix #9941
change `else if` to `else`
removed reference to button color and gradient

Changed the wording to reflect the default button's new look since it's no longer grey and doesn't have a gradient. I'd say this new wording isn't ideal and needs something a bit more, well, descriptive.