Use GitHub endpoint for Gitosis

Fixes:

    git clone git://eagain.net/gitosis.git
    Cloning into 'gitosis'...
    fatal: unable to connect to eagain.net:
    eagain.net[0: 192.237.217.227]: errno=Connection refused
    eagain.net[1: 2001:4800:7813:516:fa64:3a5d:ff04:7851]: errno=Network is
      unreachable
Update 01-chapter3.markdown

Replace `Revert` with `Switch` to avoid triggering an incorrect association with git-revert.
Merge pull request #667 from daftano/master

[it] update chapter 1
Merge pull request #669 from anaran/master

Update 01-chapter3.markdown
[nl] Chapter01: review and restructure sentences and wording

    add note to other translators, remove a number of typos and restructure
    some sentences.
Merge pull request #670 from Cpt-xx/chapter01

[nl] Chapter01: review and restructure sentences and wording
[de] Synchronize with En version
Synchronize with de version
[nl] Chapter09 Retranslate and resequence

    Retranslated the chapter and resequenced the sentences so they sound
    less Dunglish.
According to commit a0228ae there should be C3', not C3 also in other languages.
Some changes to czech version - same double part of sentence, changed inflections of 'syntax' word, 280->2^80
Merge pull request #668 from croaky/master

Use GitHub endpoint for Gitosis
Merge pull request #672 from Cpt-xx/chapter09

[nl] Chapter09 Retranslate and resequence
Merge pull request #671 from YueLinHo/master

[de] Synchronize with En version
Merge pull request #673 from engycz/master

According to commit a0228ae there should be C3', not C3 also in other la...
[it] reviewed translation chapter2