I've replaced the requirement for the pecl yaml extension with the symphony component. Sometimes I work on a windows box and the instructions for installing pecl yaml on windows looked a little intimidating:

https://code.google.com/p/php-yaml/wiki/InstallingWithPecl
Merge pull request #9 from meadsteve/symfony-yaml

Merging the use of the Symfony YAML parser, removing the requirement for the YAML extension. Thanks @meadsteve :)