[CSS] Moved the base SASS for the positioning CSS out of the media queries to optimise the resulting CSS.
Documentation: Updated links to production ZIP files.
Merge pull request #4534 from EricDunsworth/v4.0-dwnld-links

Documentation: Updated links to production ZIP files.
Merge pull request #4535 from EricDunsworth/v4.0-broken-link-fixes

Demos/Docs/Themes: Fixed various broken links.
Docs: add favicon documentation
Merge pull request #4537 from patheard/docs-favicon

Docs: add favicon documentation
Documentation: Added Web accessibility assessment methodology and accessibility responsibility breakdown documentation
Merge pull request #4538 from pjackson28/morev4docs

Documentation: Added Web accessibility assessment methodology and accessibility responsibility breakdown documentation
Fixed the english link to the Canada.ca theme
Docs: add MathML documentation
Documentation: Added input type=range polyfill documentation.
Merge pull request #4539 from patheard/docs-mathml

Docs: add MathML documentation
Merge pull request #4540 from pjackson28/sliderdoc

Documentation: Added input type=range polyfill documentation.
Merge pull request #4541 from LaurentGoderre/fix-canada-ca-link

Fixed the english link to the Canada.ca theme
Docs: add Prettify documentation
Merge pull request #4544 from patheard/docs-prettify

Docs: add Prettify documentation
Session: fix .modal-footer background colour and margin
Merge pull request #4546 from patheard/modal-footer

Session: fix .modal-footer background colour and margin
Bower: Updated to Bootstrap 3.1.0.
Partially addresses gh-4448.
Changed the message markup to use the Bootstrap panels component and removed the styles for the old message box