[it] Reviewed chapter2

Reviewed "Limiting Log Output"
[it] Reviewing chapter2

Reviewed "Using a GUI to Visualize History"
[it] chapter6

Translated "Issues with Submodules"
[it] chapter6

Cosmetic review
[it] chapter6

Added source text in english, to translate into italian
Merge pull request #730 from daftano/master

[it] updated chapter 2 and 6
[it] Edited chapter2

Cambiato storia in cronologia per essere consistente con il resto del libro
[it] Reviewing chapter2

Reviewed "Undoing Things"
[it] Reviewing chapter2

Reviewed "Changing Your Last Commit"
[it] Reviewing chapter2

reviewed "Unstaging a Staged File"
[it] reviewing chapter2

reviewed "Unmodifying a Modified File"
[it] updating chapter2

Reviewed "Working with Remotes"
[it] update chapter2

Updated titles
[it] updating chapter2

Reviewed "Showing Your Remotes"
updating chapter2

changed "we" with "I" to stay coherent with the end of the phrase.
He's talking about his own repository and his permissions.
[it] updating chapter2

Reviewed "Adding Remote Repositories"
Merge pull request #732 from daftano/en

updating chapter2
Merge pull request #731 from daftano/master

[it] update chapter 2
Merge branch 'progit/master'