Icons: Move images to sprite named folder
Icons: Use compass spriting

- Replace manual sprite with hash appended generated sprite
- base64 encode the sprite in modern browsers
- Fix relative/absolute path issue with Sass path using Ant task
Icons: Remove images duplicated from wb-icons

- Remove icons already included in the wb-icon folder
- Remove old manual sprite
Restored heading properties in IE7-8 (via grids SCSS).
Merge pull request #2380 from EricDunsworth/v3.1-grids-ie-headings

Restored heading properties in IE7-8 (via grids SCSS).
Smoothed out loading of the datepicker toggle button.
Removed colour and added icons to documentation and questions or comments buttons in working examples (#1941).
Merge pull request #2402 from pjackson28/smoothdatepickerloading

Smoothed out loading of the datepicker toggle button
Merge pull request #2403 from pjackson28/changedocbuttoncolour

Removed colour and added icons to documentation and questions or comments buttons in working examples (#1941)
Resolved merge conflicts.
Fixed intranet theme documentation link.
Resolved merge conflict.
Merge pull request #2376 from nschonni/use-compass-sprites

Use compass sprites
Icons: Added star and folder icons

New Icons:
- wb-icon-star
- wb-icon-star-empty
- wb-icon-star-half
- wb-icon-folder-search
- wb-icon-folder-bookmark
This fixes #2374 by @cfarquharson after the spriting change in #2376
Merge pull request #2404 from nschonni/additional-icons-2374-fixup

Icons: Added star and folder icons
Merge Icon spriting changes from v3.0
Icon: Fix fax icon

The previous image name didn't match the class name so the sprite
auto-generation created a different class name. Moved the demo's span to
match the rest being alphabetical.
Merge pull request #2405 from nschonni/fix-fax-icon

Icon: Fix fax icon
Merge Fax Icon fix from v3.0
Corrected markup for French Twitter Embedded Timeline example (#2409).