Update chapter19.rst

Translation up to 20% of the chapter.
Update chapter19.rst

Translation up to 36% of the chapter.
Chapter 19 - 38%

Tradução feita até o tópico "Working With Lazy Translation Objects"
Revert "Update chapter19.rst"

This reverts commit 808d01ae2dd5f3c6e8738dd6bae56456d4a6808f.
Revert "Chapter 19 - 38%"

This reverts commit 8811b6ba53db320140e6b570edf011a208b9f809.
Update chapter19.rst
Update chapter19.rst

Up to 47%
Update chapter19.rst

Up to 47%
Correcting minor typos
Update chapter19.rst

Up to 57%
Update chapter19.rst

Correcting typo
Update chapter19.rst

Up to 75%
Update chapter19.rst

Correcting typo.
Update chapter19.rst

Line 833
Update chapter19.rst
Update chapter19.rst

Revisão; até a linha 530, tópico 3
Update chapter19.rst

Revisão final
Merge pull request #72 from JoaoGFarias/master

Chapter 19