minor corrections
Merge pull request #119 from cordoval/feature/minor-quota

minor corrections
Merge pull request #120 from vibrantdavee/master

Fixed 'force page breaks' syntax for PrinceXML
Updated the CONTRIBUTORS list
Improved code quality by removing a useless 'else' clause

This error was detected by the 'code smell' inspector of PHPStorm 7
(missing return statement)
Fixed a unit test that wasn't really using its associated dataProvider
Minor code and PHPdoc fixes
Fixed the use of a unimported Exception class in the code copied
from the PrinceXML project.

This bug was detected by SensioLabs Insight (rule # 22-080):

"Missing use statement should be avoided."
Removed some commented code.

This bug was detected by SensioLabs Insight (rule # 25-085):

"Commented code should not be commited"
Added some PHPDoc to remove an "unused use statement" error
Refactored some Twig templates used to generate CSS fragments.

SensioLabs Insight suggest that Twig templates should be less than
200 lines long (rule # 37 - 010). To achieve this goal, some CSS rules
have been collapsed and the typography-related @font-face rules have
been extracted into separated Twig fragments.
Minor aesthetic tweak in the composer.json file
Removed a TODO from the processConfigurationValues() method.

The original TODO has been transformed into the issue #121 of the project.
Removed the validateConfiguration() method.

It's "impossible" to validate the book configuration because
the author can really set anything in each of the book fields
and he/she can even define any number of new fields.

In the future, it coud be possible to restrict some of the most
important fields, such as the title, the author/s name/s and the
publication date.
The user should not be able to define the slug programatically.
He/she can always modify the generated slug by renaming the
book's directory.
Removed another TODO from the code (according to the suggestions
of SensioLabs Insight).

This TODO is actually stored as the issue #59 of the project.
Removed a leftover hack introduced before the theme refactoring.
Removed another TODO from the code.

This TODO has been transformed into the issue #122 of the project.
Removed two more outdated and unnecesary TODO from the code.
Removed another TODO from the code and transformed it into the
issue #123 of the project.