Merge pull request #48 from brugnara/master

Update 04-collections.md.erb
Merge pull request #49 from brugnara/master

Update 04s-publications-and-subscriptions.md.erb
quickly reviewed and updated code snippets
restored original code snippets and commit references as for #50
Fixed #53
Fixed #51
Update 07-creating-posts.md.erb

Accenti e piccoli typo
Update 07-creating-posts.md.erb

lettera mancante
Update 07-creating-posts.md.erb

fix piccoli typo e riviste alcune frasi per miglior scorrevolezza.
Merge pull request #55 from brugnara/patch-1
more about #55
removed all trailing spaces: #55 again
.. 13s
finish cap 13s - #44
fixes #44
improved italian titles