Fix Bug 1018596: Previous and Next Buttons

Changed the previousPage and NextPage macro to include the class "neutral" so we can remove the custom styles making these blue. They still need the styles for positioning though. Yay less code!

To test: BEFORE you check this branch out, edit the previousPage and next Page macro to include the "neutral" class on the button. Have a look at a page using the macro and confirm for me that it is okay to have that class on the buttons before the style sheet change is in place.

Then checkout the branch and have a look at the result of the new styles.
Bug 1070001: Re-org Stylus - Columns

Changed columns to have 3 decimals of accuracy.

LTR now lines up on left side and doesn't need negative margin to compensate.
Fix bug 926319: Make homepage search box white
Merge pull request #2833 from openjck/926319-white-search-box

Fix bug 926319: Make homepage search box white
Bug 1072493 - Add initial testing suites
Bug 1072493: Move UI tests and improve docs
Merge pull request #2799 from stephaniehobson/BUG-1070001-reorg-stylus-cols

Bug 1070001: Re-org Stylus - Columns
Merge pull request #2813 from stephaniehobson/Bug-1018596-prev-next-buttons

Fix Bug 1018596: Previous and Next Buttons
bug 1084003 - require two peer review and at least one owner for database migration changes
Merge pull request #2835 from jezdez/migration-reviews

bug 1084003 - require two peer review and at least one owner for database migration changes
Merge pull request #2832 from openjck/pr2770-updates

Bug 1072493 - Add initial testing suites
Bug 1084550: Flame Ads

Custom styles to support Flame ads macro. To test, copy https://developer.allizom.org/en-US/docs/Template:flame to your local dev and involk as {{flame(0)}} or {{flame(1)}}
Merge pull request #2839 from stephaniehobson/BUG-1084550-flame-ads

Bug 1084550: Flame Ads
Fix bug 1083463: Increase search letter-spacing