Clarify number of columns in nested grid

BS3 commits: a13d459491d800fe182a9217da9dd740cd6b57a9
Fixes 11795: Update the contributing guidelines to include some more CSS guidelines

BS3 commits: 540677c42adc6771d9e755f5a3c2bd5887611ec9
Fixes 11783: Document requirement of .container(-fluid) in navbars

BS3 commits: 93a4d6cc5ecdc1cbc09c4b8af2e587f4480b36cf
Improve pager customization

BS3 commits: f126411735dc00c72c4c8cb7421852eb1652255a
typo

BS3 commits: ee80b5e1d4d36f37ec0408bbe2af7e4c2e5cb0d5
Don't exclude fonts from bower installs

BS3 commits: e7a56df5a2bdf10b16ed2e256eed6e9bd3fe8259
Drop redundant module import

BS3 commits: 0c457d48f85ad637d9c47b5167b83e8de2b868d6
revert an earlier change to move the component-animations.less file because it fubared modal backdrop .fade usage

BS3 commits: f5c13a3e1b2beef5e3335a710993ff8b383d76f7
Fixes 11660: Depcreate small and .small in blockquote in favor of footer

BS3 commits: 393d523cdbf14c4522ed13dca701120aeded352c
formatting and comment

BS3 commits: 4f22670c6ecfd4239fe690719867531c18721234
Fixes 11266: Apply a pixel-based line-height to date inputs for iOS 7

BS3 commits: d9345ff7d55e3982b36f88cb7459239a773bbfda
Add new form feedback states, clean up existing form styles

BS3 commits: 2979e4bcea25c428c801d77153dc0f663618ce20
remove some duplication
Fixes 10492 again, this time for last row's corners on striped tables

BS3 commits: 4ee93c9f8529cfeef56d4178b91e1ddcb0bff09c
copyediting

BS3 commits: be508e043c2a5f53b352066a1628693adfa7755e
fix var name in example to follow JS conventions

BS3 commits: 023731b4c74cac72f55299502a34eb5ef88b8db0
fix typo in docs

BS3 commits: a2f7c3015eb433702163a7b307e9424816f22e7a
use unique IDs for modal labels in doc examples so HTML validates

BS3 commits: f8cee54f4bd59c4c311a39d3a1d482489125c585
use unique IDs for input feedback examples so HTML validates

BS3 commits: 94bdea00541f5fd1e327cfcf8fc0dba0a8b624c0
explicitly set more HTML5 validator options

BS3 commits: 75db35507322ad02ded7fe32a2e74dcf3f4c58cf