Don't mention Git of pre-1.6 versions.

Git-1.7 was released more than three years ago, so it's safe to
assume that there are very few people still using Git of pre-1.7
versions and no one using pre-1.6.
Add an example on `**/` pattern to the example of .gitignore file.
Add --word-diff option description
Eliminate "folder" word usage.
Fix a typo on Dia-version of figure 5.15.
Merge pull request #404 from GArik/EN

[RFC] Attempt to modernize text a bit
[zh] Fix tables with correct tab characters
[pt-br] Fix tables with correct tab characters
[de] Fix some typos in chapter 3(.0)
[de] Fix some typos in chapter 3.1
[it] Chapters 1-4: Apply uniform style of translation. Minor corrections. Update the translation.
[ja] Apply ccffb46d687bfb1c005965e0b49e27d05e816673
[ja] Apply bc3f922f2549e44524dc11301d1e53c984b14a1b
[ja] Apply b294744d98a6f6cdbc3508b0058f8616147c1596 and fix typo
Merge pull request #407 from harupong/ja-chapter1

[ja] Apply rest of the unapplied commits to ja chapter 1
[ja] Apply ccffb46d687bfb1c005965e0b49e27d05e816673
[ja] Apply b294744d98a6f6cdbc3508b0058f8616147c1596 and fix typo
[ja] Apply bc3f922f2549e44524dc11301d1e53c984b14a1b
Merge pull request #406 from tecnomente/master

[it] Chapters 1-4: Apply uniform style of translation. Minor corrections. Update the translation.
[ja] fix bug introduced by #407