Fixed the feature on Unix systems

The Yaml dumper is quoting values containing a space but not values
without spaces. The default temp folder does not have a space on Unix
systems, while it depends on the user name on Windows.
Removed usage of the deprecated class on Symfony 2.4+
Ensured a consistent default error reporting level for PHP 5.4 and 5.5

E_ALL includes E_STRICT as of PHP 5.5 but it was not the case in PHP 5.3
and 5.4. The default value for the error reporting now includes E_STRICT
for all versions to be consistent.