highlight the existence of git 'tree' object type to distinguish it (e.g. from file system tree)
Italian translation for section 7.2
update readme for general contribution guidelines
Add reference to the online version at git-scm.com to README
Merge branch 'update_readme'
Merge branch 'master' of https://github.com/progit/progit into translation-it-chapter-7
Update Gitolite documentation link for zh
Merge pull request #399 from hlee/master

#214 for zh version
Italian translation for section 7.3
Merge pull request #400 from dghilardi/translation-it-chapter-7

Translation it chapter 7
[de] Use "Du", "Deinen",... instead of "du", "deinen"

- See also http://www.duden.de/sprachwissen/sprachratgeber/gross-oder-kleinschreibung-von--em-du-du--em--und--em-ihr-ihr--em--1
   Use capitalized letters because in first parts of the book they are also used.
[de] Fix typos
[de] Improve german translation of chapter 7.1
[de] Use markdown extension for README file
[de] Use markdown syntax in german README file
Merge pull request #401 from fernsehkind/master

[de] Improve german translation of chapter 7.1
[ja] Rename README to README.md
[ja] Update README.md
[ja] Apply 3 commits of en to ja
Hunk1: apply @8526500 to ja
Hunk2: apply @a8d1e03 to ja
Hunk3: apply @67bc107 to ja
Merge pull request #403 from harupong/ja-chapter7

[ja] Update chapter7 and README