[ja] Apply 192518071147606e2e966ddb4d6ed7252c6a1988
Merge pull request #454 from harupong/master

[ja] Update chapter4
improvements in chapter 6, translation of section 6.4
[pl] translation of section 6.5
Add "thanks:" to the ja section of latex/config.yml
[pl] translation of section 6.6
[pl] translation of sections 6.7 and summary
Merge pull request #455 from gibas/06-git-tools

[pl] improvements in chapter 6, translations of the rest of that chapter
[ru] chapter 2: Corrected typo "репозиторями"
[pl] translated first part of chapter 8
Modify "thanks:" at the ja section of latex/config.yml
[pl] translation of section 8.1
Updated readme with MacOS dependencies.
[pl] translation of section about importing from Subversion repository
[pl] translation of section about import from Perforce
[pl] translation of sections about importing from other SCMs and summary
Update 01-chapter9.markdown
[pl] translation improvements in chapter 8
[pl] translation of section 9.1 and guidelines update
[pl] translation for polish version of pdf in config.yml