Fix BL-794 by keeping the cog at the bottom of the edit box.

We keep it there by adjusting the "bottom" property of the cog every time the scroll of the parent edit box changes.
Updated French Translation File from David Rowe
Fix BL-625, where imageInMiddle pages looked wrong when multilingual

The problem was that the CSS "calc" was failing because of lack of units on the SpaceBetweenMultilingualAlternatives variable.
Merge pull request #195 from BloomBooks/BL-794FormattingButtonPositioning

Fix BL-794 by keeping the cog at the bottom of the edit box.
Merge pull request #196 from BloomBooks/BL825ImageInMiddleCalculations

Fix BL-625, where imageInMiddle pages looked wrong when multilingual
Fix xmatter mixin that marked all cover pages as frontcover
Introduce less version of factory-xmatter, with no changes.
Add a new xmatter pack named "traditional"

 This puts the credits page on the back of the title page, rather than the inside of the front cover. This is good in cases where you pay by the page imprint, rather than by pieces of paper. You can select it from Settings:Book Making:Front/Back Matter Pack. Once you have chosen this, you won't see it on any existing books until you do these steps: In the Collection Tab, click on the little triangle, then select "Advanced: Do Updates of All Books".
Merge pull request #197 from BloomBooks/TraditionalXMatterPack

Add a new xmatter pack named "traditional"