[BUGFIX] Restore libxml error handler state after clearing
[TASK] Add Packagist badges to the Readme.
Merge pull request #66 from jjriv/task/badge

[TASK] Add Packagist badges to the Readme.
[BUGFIX] Wrong selector extraction from minified CSS
[BUGFIX] Selectors with attribute only
Merge pull request #69 from OzzyCzech/minifyCssParsingError
Merge pull request #67 from OzzyCzech/invalidXpathAttributeSelector
[FEATURE] Preserve @media if necessary
Fixed #1
Merge pull request #62 from OzzyCzech/ignoreMediaQuery
[TASK] Use PHPUnit via Composer.

This change also allows unit tests to use the Composer autoloader
for loading the Emogrifier class.
Merge pull request #70 from jjriv/task/composer-phpunit

[TASK] Use PHPUnit via Composer.
[CLEANUP] Use spaces for indentation in composer.json.
Merge pull request #72 from jjriv/cleanup/space-indentation-in-json

[CLEANUP] Use spaces for indentation in composer.json.
[BUGFIX] Do not PHP-lint the files in vendor/.

The PHP lint in .travis.yml checked _all_ PHP files, including those
in vendor/ (which are not our responsibility).

This change switches the lint to only check the files in the Classes/
and Tests/ directories.
Merge pull request #74 from jjriv/bugfix/php-lint

[BUGFIX] Do not PHP-lint the files in vendor/.
[TASK] Install PHP_CodeSniffer via Composer instead of via PEAR.
Merge pull request #73 from jjriv/task/composer

[TASK] Install PHP_CodeSniffer via Composer instead of via PEAR.
[BUGFIX] Escape all backslashes in strings.

The regular expression in parseCssDeclarationBlock contained a single
unescaped backlash. This change escapes that backslash.
Merge pull request #75 from jjriv/cleanup/double-slash

[BUGFIX] Escape all backslashes in strings.
[FEATURE] Add cache

Improve speed by adding cache to function parseCssDeclarationBlock.