Update Bootstrap to 3.1.1

This version fixes an issue with affix, used in the side navigation.
Implement floating nav with Bootstrap's scrollspy
Style floating nav with visual design

Also add support for Bootstrap affix to keep nav in window while scrolling.
Update the content layout for the floating nav

It now matches the proper layout from the visual design PSDs.
Add floating nav to changing and open access content pages
Merge remote-tracking branch 'culds/master' into avocet/content-floating-nav

Conflicts:
	avocet/what-do-i-need-to-do.html
	avocet/what-is-changing.html
	avocet/what-is-open-access.html
Review follow up

- Tweak whitespace in avocetfloatingnavigation.html
- avocetfloatingnavigation.css:
  - Add license header
  - Scope all styles to .avocetfloatingnavigation-wrapper
  - Order properties (where appropriate)
  - Add newline at end of file
- avocetfloatingnavigation.js:
  - Move rendering into a function
  - Fix some comments
  - Use new widgetsready event to detect page load
Merge remote-tracking branch 'culds/master' into avocet/content-floating-nav

Conflicts:
	avocet/css/avocet.base.css
	avocet/what-is-changing.html
More review follow up:

- avocetfloatingnavigation.js:
  - Change render() to renderNavigation()
  - rm $navigation var
  - use scrollElementSelector instead of calling .data() again
  - add missing semicolon
- avocetfloatingnavigation.css:
  - upper case hex colours
Review follow up:

- Change doc comments on constants to regular comments
- Remove error detection/handling
- Don't line break long comments
- Move jQuery selectors and data attr accesses inline in expressions
  which use them instead of naming them with variables up front.
- Quote Object literal keys
Add bootstrap.showhide plugin

It fixes jQuery's show() and hide() functions when using Bootstrap's hide/hidden/show classes, which have started to use !important...
Merge remote-tracking branch 'culds/master' into avocet/content-floating-nav

Conflicts:
	avocet/css/avocet.base.css
Change bootstrap.showhide plugin for better compatibility

Now the bootstrap visibility classes are only added to elements which
already have bootstrap visibility classes on them. This avoids issues
with code which uses methods other than jQuery's show/hide methods to
hide/show elements.
Merge pull request #174 from ucamhal/avocet/content-floating-nav

Add side floating navigation to the content (about) pages