Updated atlas.json
Adding callout images.
Putting image alt text that contains commas in quotes.

Conflicts:
	book/01-introduction/sections/basics.asc
Fixing duplicate id.
Merge pull request #201 from progit/epub-fix

Epub Fixes
difftool reference?
Merge branch 'epub-fix'
try just changing it
Fix typo
Merge pull request #202 from harupong/ch06-typo-fix

Fix one typo
Fix typo
Merge pull request #206 from MasoodFallahpoor/ch06-typo-fix

Fix typo
Small grammar fix: replaced "it's" with "its"
Merge pull request #207 from dtikhonov/master

Small grammar fix: replaced "it's" with "its"
Fixed typo: "walk through," not "walk though."
Merge pull request #208 from dtikhonov/master

Fixed typo: "walk through," not "walk though."
Fix a typo in "contributing" section of chapter 6
Merge pull request #209 from MasoodFallahpoor/ch06-typo-fix

Fix a typo in "contributing" section of chapter 6
Merge remote-tracking branch 'upstream/master'

Conflicts:
	book/01-introduction/sections/basics.asc
	book/02-git-basics/sections/recording-changes.asc
	book/03-git-branching/sections/rebasing.asc
	book/04-git-server/sections/git-daemon.asc
	book/04-git-server/sections/smart-http.asc
	book/06-github/sections/1-setting-up-account.asc
	book/06-github/sections/2-contributing.asc