[book] 1st to 4th ch changes#6252

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talitakz wants to merge 6 commits intosymfony:2.3from

talitakz:book-intro-text-modif

Commits on Feb 10, 2016

[] changes in the first four ch of the book
talitakz
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Commits on Mar 18, 2016

changes according to comments after PR + some other typos
talitakz
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