fix #12154
Fix #12025 and minify styles
fix #12007 by clarifying target of dropdown events
refactored and renamed grid mixins
fixed first element padding of list-inline
rm callout about creating .container-fluid-alikes now that .container-fluid has been added
Remove redundant :-moz-placeholder styles

No need for old Firefox versions support.
Improve alignment of the dashboard placeholder images
Fixes #12435
Allow the bootstrap package in npm to expose css and less
fixed two typos in carousel.less

carousel.less has two typos in glyphicon classnames. fixed them.
Docs: losslessly compress images.

Before: 25,1 KB (25.773 bytes)
After:  23,7 KB (24.352 bytes)
Compress examples screenshots with kraken.io.

Before: 1,12 MB (1.174.728 bytes)
After:  1,11 MB (1.173.614 bytes)
Sticky footers without any wrappers
Merge pull request #12512 from ZDroid/placeholder-img-fix

Improve alignment of the dashboard placeholder images
Merge pull request #12025 from ZDroid/clean-visibility-mess

Fix #12015 and minify styles
grunt dist--includes changes from #12025 and decimal changes, likely from a change in dependencies
possibly avoid some extra S3 charges

Refs https://github.com/boto/boto/issues/2078
add basic back to top link to docs sidenavs, fixes #12589
Merge pull request #12534 from Techwraith/patch-1

Allow the bootstrap package in npm to expose css and less
Merge pull request #12465 from XhmikosR/docs-img

Docs: losslessly compress images.