Fixed typo ALC -> ACL
Update service_container.rst
Update the_big_picture.rst

Update : some path errors and missing information.
Update security.rst

Correct file path mentioned in comment
Added translation cookbooks about session
Re-phraser de certains paragraphes.
Correction d'une faute de grammaire

La plupart résident => La plupart réside
Merge pull request #521 from emagma/patch-2

Fixed typo ALC -> ACL
Merge pull request #522 from NAYZO/patch-4

Update service_container.rst
Merge pull request #523 from LeGauloisFR/patch-1

Update the_big_picture.rst
Merge pull request #526 from netgusto/patch-3

Re-phraser de certains paragraphes.
Merge pull request #527 from symfony-fr/2.4

Merging 2.4
Merge pull request #524 from TNT-razor/patch-1

Update security.rst (Correct file path mentioned in comment)
Merge pull request #525 from saro0h/session

Added translation cookbooks about session